Chess endgame
In chess, the endgame is the final phase of a game that occurs after the middlegame, when most pieces have been captured or exchanged, leaving primarily kings, pawns, and a limited number of other pieces on the board.[1] This stage emphasizes precise play, as even small advantages can lead to victory, with the primary objectives often revolving around promoting a pawn to a queen or forcing checkmate using the remaining material.[2] Unlike the opening and middlegame, where development and control of the center dominate, the endgame transforms the roles of key pieces: the king becomes an active fighter rather than a liability to protect, while pawns gain significant power due to their potential for promotion and ability to create passed pawns that advance unhindered.[3] Common endgame types include king and pawn endings, rook endings, and minor piece endings (such as bishop or knight pairings), each governed by specific theoretical positions that determine win, loss, or draw outcomes based on factors like pawn structure and king positioning.[4] Fundamental principles guide endgame strategy, including centralizing the king to support pawns and restrict the opponent, obtaining the opposition (a key concept where one king forces the other to yield control of critical squares), and advancing passed pawns aggressively while using rooks to support them from behind.[3] Additional tenets involve exchanging pieces when ahead in material (to simplify toward a winning pawn majority), avoiding pawn weaknesses on the same color as the opponent's bishop, and calculating accurately to avoid stalemates or zugzwangs.[4] These principles apply across various material imbalances, from basic checkmates with king and queen versus king to complex rook endgames where activity often trumps static advantages. Studying endgames is crucial for chess improvement at all levels, as it enhances calculation depth, piece coordination, and positional understanding that carry over to earlier phases, while enabling players to convert middlegame edges into wins and salvage difficult positions.[5] Theoretical endgames, such as the Lucena or Philidor rook positions, form the foundation of this study, with resources like practical exercises reinforcing their application in real games.[3]Definition and Characteristics
Defining the Endgame Phase
The endgame represents the concluding phase of a chess game, emerging after the middlegame through substantial exchanges of pieces and often the queens, resulting in a simplified board with limited material—typically fewer than three minor pieces or equivalent per side alongside pawns and the now-active kings. Unlike the opening's focus on development or the middlegame's tactical complexities, the endgame shifts emphasis to precise calculation, pawn promotion as the central objective, and the king's transformation from a defensive piece to an aggressive attacker that can traverse the board to support advances or deliver checkmate. This phase demands evaluation of subtle advantages, such as passed pawns or superior king position, where even a single pawn can decide the outcome due to the reduced forces.[2] The study of endgames traces its origins to the 18th century, pioneered by François-André Philidor in his seminal 1749 work Analyse du jeu des Échecs, where he analyzed critical positions like rook and pawn endings, famously declaring pawns the "soul of chess" for their structural importance in the finale. Philidor's insights marked a departure from tactical dominance toward positional understanding, influencing subsequent composers and theorists through the 19th century, including contributions from figures like Josef Kling and Bernhard Horwitz who composed intricate studies. By the 20th century, dedicated endgame treatises by authors such as Reuben Fine in Basic Chess Endings (1941) systematized theoretical knowledge, while modern computational advances, including endgame tablebases developed since the 1970s, have exhaustively solved all positions with seven or fewer pieces, providing perfect play evaluations and refining classical theory.[6][7] The shift to the endgame occurs gradually, signaled by criteria such as the simplification of pawn structures—often through captures that create passed pawns—and the king's safe centralization, freeing it from castled safety to contest key squares. Pawn promotion races become paramount, with players maneuvering to advance connected or outside pawns while blockading the opponent's. Material reduction serves as a rough metric, with endgames commonly featuring 8-12 total points per side (using standard valuations: pawn=1, minor piece=3, rook=5), exemplified by positions like king, rook, and two pawns versus king and three pawns, where zugzwang or opposition can tip the balance. These transitions highlight the endgame's strategic depth, where imprecise play in earlier phases can prove decisive.[2]Key Principles and Strategies
In chess endgames, the king transforms from a defensive piece into an active attacker, with centralization being a cornerstone principle to maximize its influence across the board. Positioning the king toward the center allows it to support pawn advances, restrict the opponent's king, and contest key squares more effectively, often turning a draw into a win. For instance, in king-and-pawn endings, the rule of the square provides a geometric method to assess whether the opposing king can intercept a pawn before promotion: imagine a square formed by the pawn's file and the number of ranks remaining to the promotion square (e.g., a pawn on the fifth rank creates a 4x4 square); if the enemy king can enter this square on its next move, it can catch the pawn, but if not, the pawn likely promotes.[8][9] Pawn structure plays a pivotal role in endgame success, particularly through majorities and passed pawns, which create imbalances exploitable for promotion. A pawn majority on one wing—such as three pawns against two—enables the creation of a passed pawn by advancing the unopposed pawns, as the opponent cannot block all advances simultaneously; this outside passed pawn then draws the enemy king away, allowing breakthroughs elsewhere. Passed pawns, unhindered by enemy pawns on adjacent files, gain value as they advance, especially on the seventh rank, where they become a potent threat: the pawn threatens to advance to the promotion square, forcing the opponent to capture it with the king (often losing tempo) or allow promotion.[10][4] Zugzwang, a position where any legal move worsens the player's situation, is a forcing technique essential for converting slight advantages, particularly when the opponent has no constructive moves left. In a classic example, consider a rook endgame where White's rook controls the seventh rank, pinning Black's pawns, but Black's king is active; White maneuvers into zugzwang by first securing the opposition, compelling Black to move their king away and lose control of a key pawn. Triangulation complements zugzwang by allowing a player to lose a tempo deliberately, often with the king forming a triangle on three squares (e.g., Kg1-Kf2-Ke3-Kf2), handing the move back to the opponent in a symmetrical setup to force them into zugzwang.[11][12] In symmetrical positions, where material and structure mirror each other, gaining a tempo through waiting moves becomes crucial to disrupt equilibrium and induce zugzwang. A waiting move, such as shifting a rook along the back rank (Ra1-Rb1-Ra1) without changing the position's essence, provokes the opponent into committing first, potentially exposing weaknesses; this is especially effective when the opponent lacks safe pawn moves, forcing their king or pieces into inferior spots. Tempo management thus amplifies small edges, as even one extra move can secure opposition or support a pawn push in balanced endings.[13][14] Endgame evaluation hinges on material, space, and activity, with rough point values providing a baseline: a rook approximates 5 points, a bishop or knight 3 points, and a pawn 1 point, though these are static and must be adjusted dynamically. Activity enhances value significantly—a centralized rook attacking pawns may outperform a passive queen (9 points), while space control (e.g., pawns advanced to cramp the opponent) and king activity can outweigh minor material deficits, as seen in positions where a passed pawn's promotion potential tips the balance despite equality elsewhere.[15][4]Basic Endgames Without Pawns
Fundamental Checkmates
Fundamental checkmates in chess endgames refer to the basic techniques for delivering checkmate using a king and one or two pieces against a lone king, without pawns. These combinations form the foundation for more complex endgames, teaching principles of piece coordination, king opposition, and driving the enemy king to the board's edge. Mastery of these mates is essential, as they occur frequently in practical play and underpin strategies in pawnless endings.[16] The queen versus king checkmate is the most straightforward, relying on the queen's power to restrict the enemy king's movement while the attacking king provides support. The primary technique involves using the queen to outflank and oppose the enemy king, gradually shrinking its safe squares until it reaches the edge. A key pattern is the "staircase mate," where the queen delivers a series of checks in a stepping motion (e.g., from d8 to f6 to h4), forcing the king backward toward a corner like h8, with the attacking king advancing to oppose and deliver the final mate, such as Qh3#. King opposition is crucial here to prevent escape, but common errors include failing to centralize the queen early or allowing stalemate by over-restricting the king without checks.[16][17] In the rook versus king checkmate, the rook's linear control excels at cutting off the enemy king from ranks and files, driving it to the edge through methodical checks. The cut-off method positions the rook to block the king's lateral movement (e.g., on the sixth rank to confine it to the last two), while the attacking king advances to gain opposition and support the mate. Typical patterns include the rook checking from the side or rear to force the king to a corner, culminating in a mate like Rh1 with the king on g2. Precursors such as the Lucena (winning) and Philidor (drawing) positions in rook-pawn endings illustrate rook usage but apply here in pure form by emphasizing cuts and coordination; errors often arise from premature rook placement on the edge or neglecting opposition, leading to king escapes or stalemates.[16][18] Two bishops versus king requires precise coordination, as the bishops control complementary diagonals to herd the enemy king toward the edge. The technique funnels the king using bishops on adjacent diagonals, with the attacking king blocking flight squares to force it into a corner for mate. Effective patterns involve the bishops sealing off escape routes, mating in any corner (e.g., bishops on f7 and g5 supporting Kg7 vs. Kh8), though the process demands the attacking king actively advance. Misaligning the bishops or delaying king support commonly allows the enemy king to centralize, while stalemate traps occur if bishops overly restrict without checks.[16] The bishop and knight versus king checkmate is the most challenging fundamental mate, possible only by driving the enemy king to a corner matching the bishop's color square. Coordination is key: the pieces form a "cage" to restrict the king, with the knight and bishop alternating checks to shrink its territory, often taking up to 33 moves from the worst position. A critical pattern is the "wazir" or "W-maneuver," where the knight traces a W or V route (e.g., knight to e5-f7-g5) to block the king's escape while the bishop covers diagonals, forcing it to the correct corner like a1 for a light-squared bishop. Philidor's maneuver serves as a precursor, guiding the knight's path; common pitfalls include targeting the wrong corner (leading to draws), poor piece harmony, or mechanical repetition that invites stalemate.[16][19]Pure Piece Combinations
In pure piece endgames, which involve only kings and non-pawn pieces on the board, outcomes depend heavily on material imbalances, piece mobility, and king activity, often leading to draws unless one side can exploit coordination or force zugzwang positions. These endgames emphasize restriction, separation of enemy forces, and precise maneuvering, where the absence of pawns removes promotion threats but heightens the role of perpetual checks or stalemates. Unlike basic checkmates, these configurations explore nuanced winning chances and defensive resources. The rook versus bishop endgame is typically a draw with optimal play, as the bishop's defender can maneuver the king to a safe corner of the opposite color from the bishop's diagonals, preventing the rook from delivering checkmate. The rook side wins only if it can drive the enemy king into the "wrong" corner—same color as the bishop—through aggressive checks and king opposition, restricting the bishop's scope. Similarly, in rook versus knight endgames, the rook generally prevails by separating the knight from its king and capturing it, though the knight's leaping ability allows draws if it remains centralized or the defending king supports it effectively.[20][21] Bishop versus knight endgames are drawish overall, but the bishop holds a slight edge in open positions where its long-range mobility outpaces the knight's short-range hops, enabling better control of key squares. In closed or cramped setups, the knight can equalize by hopping to strong outposts, but without pawns to dictate structure, neither piece can force a win alone against active defense.[22] Two knights versus a lone king is generally a draw due to stalemate risks; while checkmate positions exist, they cannot be forced, as the defending king can always move to avoid them or reach a stalemate trap. Exceptions arise only with external threats like pawn promotion, but in purely pawnless scenarios, the knights lack the power to coerce the king into a mating net without cooperation.[23] Three minor pieces versus a rook offers strong winning chances for the minor pieces side, particularly if including bishops for diagonal coordination, as they can overwhelm the rook's linear attacks and force trades or zugzwang. Knights in this imbalance provide flexibility but require careful harmony to avoid rook incursions; overall, the numerical and cooperative advantage typically secures victory unless the rook centralizes aggressively.[24] The active king plays a pivotal role in these endgames, often infiltrating to support piece trades, enforce zugzwang, or block escapes, turning theoretical draws into practical wins through superior activity. For instance, the stronger king can outflank opponents to zugzwang them into unfavorable exchanges. Historical examples from composers like Alexey Troitzky illustrate these dynamics, with his studies showcasing intricate rook-minor piece battles and knight coordinations that highlight zugzwang enforcement and king activity in pawnless settings. Troitzky's compositions, such as those involving multiple minors restricting a rook, demonstrate winning paths through precise geometry and tempo control.[25]Single Pawn Endings
King and Pawn vs King
The king and pawn versus king endgame represents the most fundamental pawn ending in chess, where one player possesses a king and a single pawn opposed by the opponent's lone king.[26] Victory for the side with the pawn hinges on whether its king can support the pawn's advance to promotion, while the defending king aims to capture the pawn or restrict the attacking king's activity.[26] Central to this endgame are concepts like opposition and geometric rules that determine if the pawn can queen or be stopped, with outcomes varying sharply based on the kings' relative positions and the pawn's file and rank.[26] Endgame tablebases confirm that all such 3-piece positions are classified as either wins or draws, with maximum distances to win around 16 moves for promotion. A primary tool for evaluating unsupported pawn advances is the rule of the square, which assesses whether the defending king can intercept the pawn before it promotes. To apply it, imagine a square with the pawn at the far corner from the promotion square, extending along the pawn's file to the eighth rank and perpendicularly across adjacent files for a side length equal to the number of ranks remaining (9 minus the pawn's current rank for White). For a central pawn on the fourth rank like e4, this forms a 5x5 square spanning files a to e and ranks 4 to 8 (adjusted for board edges). If the defending king is outside this square and it is the pawn's turn to move, the pawn can promote without interference, assuming no king involvement; otherwise, the king may enter and capture.[26] This rule simplifies calculation when the attacking king is distant, as seen in positions where a pawn on the fifth rank (e.g., f5) forms a 4x4 square, and the defender outside it loses the race.[26] Opposition is another cornerstone, referring to positions where the kings confront each other on the same rank or file with one square between them, limiting the opponent's movement.[26] There are three main types relevant to this endgame: direct opposition, where kings are two squares apart on a rank or file, allowing the player with the move to force the opponent back; distant opposition, occurring when kings are separated by an odd number of squares (e.g., three squares apart), enabling the attacker to gain tempo for pawn support; and diagonal opposition, where kings oppose along a diagonal, often used to maneuver toward key squares.) For instance, with a pawn on the sixth rank (e.g., f6) and kings on f7 and f8, the defender gains a draw by taking direct opposition with ...Kg8, blocking the pawn's path.[26] Key positions include the attacking king two squares away from the defender on the pawn's file, where seizing opposition allows penetration to support promotion.[26] Critical squares dictate winning chances when the pawn reaches the fifth rank, as they are the positions the attacking king must occupy to guarantee promotion. For a pawn on the fifth rank (e.g., f5), these are the three squares two ranks ahead on the seventh rank (e.g., e7, f7, g7), adjusted for edges.[26] If the attacking king reaches one—such as f6 for a f5-pawn—it forces the defender back, enabling the pawn to advance safely (e.g., 1. Kf6! wins by controlling the promotion path).[26] On the sixth rank, the attacking king in front or beside the pawn typically secures the win, but the defender draws by occupying the queening square or using opposition to capture.[26] Certain configurations lead to drawing zones, particularly with rook's pawns (a- or h-file), where the defender can hold even against an active attacking king. If the pawn is on the a- or h-file and the defending king reaches the corner (e.g., a8 for a white a-pawn) or adjacent squares (e.g., b8, c8), it draws by stalemate or pawn capture, as the attacker cannot force promotion without allowing a draw.[26] For a pawn on the second rank, the draw holds unless the attacking king crosses to the sixth rank on the same wing; knight's pawns (b- or g-file) are often drawn due to similar edge restrictions.[26] Insufficient king support, such as the attacker being too far to contest these zones, results in a draw regardless of pawn structure.[26]Opposition and Related Concepts
Opposition is a fundamental concept in pawn endgames, where the kings confront each other directly, typically with one square separating them on the same rank, file, or diagonal, allowing the player who does not have to move to control key squares and restrict the opponent's king.[27] This positional advantage often determines whether a pawn can advance to promotion without interference. There are three primary types: direct opposition, where kings are two squares apart on a rank or file; diagonal opposition, where the kings are separated by one square along a diagonal; and distant opposition, where kings are farther apart but aligned such that the parity of moves maintains control, often leading to direct opposition.[27] These types enable the active king to block the enemy king from accessing critical squares near the passed pawn.[28] In single-pawn advances, gaining opposition allows the attacking king to support its pawn while blocking the defender from capturing it, often deciding if promotion occurs. For instance, if White's pawn is on e5 with kings on e3 (White) and e6 (Black), White can maneuver to secure opposition on e4, preventing Black's king from capturing the pawn and allowing White's to advance safely.[29] The side with the move may lose opposition if already aligned, but distant or diagonal opposition can regain it, ensuring the supporting king arrives in time.[27] Triangulation is a technique to deliberately lose a tempo with the king, forming a triangular path (two moves forward and one back) to regain opposition and force the opponent into zugzwang. This is useful in single-pawn positions where the attacker needs to maneuver the king past the defender without losing tempo.[30] For example, with the White king on d4 and pawn on e4, Black king on f5; White triangulates by moving to c3-d3-c3, forcing Black to move first and yield opposition, allowing White's king to advance and support the pawn.[31] Outflanking occurs when the attacking king maneuvers around the defending king to bypass opposition and reach the pawn's promotion path. In a single-pawn setup, if the Black king blocks directly on the file (e.g., White king on a3, pawn on a4, Black king on c5), White's king can shift sideways (e.g., to b2-a2) to outflank via an adjacent file, supporting the pawn's advance while sidelining the defender.[32] This tactic allows the outflanking king to shoulder the opponent aside and secure promotion.[33] Endgame tablebases, such as Syzygy, solve all king and single pawn vs. king positions exactly, confirming theoretical outcomes as wins or draws based on precise king and pawn placement.Minor Piece Endgames with Pawns
Knight and Pawn Configurations
In knight and pawn endgames, the knight's ability to jump over pieces allows it to fork the enemy king and support pawn advances, but its slower mobility compared to a bishop often hinders rapid pawn promotion efforts.[34] The knight excels in tactical maneuvers like forks to guard key squares, yet its effectiveness diminishes in open positions where long-range control is needed for pawn support.[35] In the configuration of a knight and pawn versus a lone king, the knight facilitates the pawn's advance by forking the opposing king away from critical squares, enabling the pawn to gain tempo and promote. However, this process is notably slower than with a bishop, as the knight requires multiple moves to reposition effectively, giving the defending king more opportunities to contest the promotion path.[36] A representative example involves the knight maneuvering to d5 in a central pawn structure, forking the king on e7 and allowing the pawn to push to the seventh rank unopposed.[37] When a knight faces one or more enemy pawns, it can capture isolated pawns through tactical infiltration, but it struggles significantly against passed pawns on the board's edges, such as a- or h-file pawns, due to limited safe attacking squares. In such cases, the knight often fails to blockade effectively without king support, allowing the pawn to promote if the defending king is distant. For instance, in a study by M. Neumann from 1926, the knight overcomes an apparently unstoppable edge passed pawn only through precise calculation, highlighting the need for accuracy in these precarious positions.[34] The two knights versus a single pawn endgame requires precise coordination to blockade the pawn and prevent promotion, often succeeding if the pawn is positioned behind the Troitzky line (a4-b6-c5-d4-e4-f5-g6-h4). One knight typically blocks the pawn directly, while the other, supported by the king, drives the enemy king toward a corner where checkmate becomes feasible, though this can exceed 50 moves and ignore the 50-move rule in theoretical analysis. In the game Karjakin vs. Sevian from the 2018 Chess.com Isle of Man International Masters, despite the pawn advancing beyond the Troitzky line (theoretically drawable), the two knights successfully blockaded it and won due to the defending king's suboptimal positioning.[38][39] In knight and pawn versus knight endgames, material equality shifts focus to pawn activity and establishing outposts for the knights on strong central squares like d5 or e5, where they control multiple key points and restrict the opponent's knight. The side with the more active pawn structure can create passed pawns or zugzwang positions to force concessions, as knights' slow speed favors the player who centralizes their king first. A key outpost on an advanced, undefended square often decides the outcome, turning a drawn material balance into a win through superior piece placement. Knights exhibit limitations in pawn endgames due to their inability to control long diagonals, rendering them ineffective against passed pawns on colors or files where repositioning takes too many moves, particularly on the edges where fork opportunities are scarce. Unlike bishops, which are strictly color-bound, knights alternate colors but still face challenges supporting pawns on opposite-color complexes without tactical support, often leading to stalemates or insufficient pressure.[37] A seminal study illustrating underpromotion to a knight is Harold Lommer's AUW composition from 1933, where White promotes sequentially to knight, bishop, and rook to avoid stalemate and secure victory: 1.fxg8Q! hxg1Q+ 2.Qxg1 Kb3 3.c8S! Rb5 4.d8B! Re5 5.e8R! Rxe8 6.Be7 wins. This demonstrates the knight's unique forking potential in precise endgame tactics.[40]Bishop and Pawn Configurations
In bishop and pawn versus king endgames, the bishop aids the king in promoting the pawn by controlling long diagonals that intersect the pawn's path, often adapting the rule of the square from pure pawn endgames to account for the bishop's influence on key approach squares.[41] The attacking king typically gains the opposition to support the pawn's advance, while the bishop restricts the defending king's entry into the promotion square's vicinity. This configuration is generally winning unless the defending king is sufficiently close to contest the promotion effectively.[41] A notable exception arises with the wrong-color bishop, particularly against rook pawns (on the a- or h-file), where the bishop cannot control squares of the promotion square's color, allowing the defending king to blockade the pawn without interference.[42] For instance, a light-squared bishop paired with an h-pawn promoting to h8 (a dark square) often results in a draw, as the bishop fails to attack the critical corner, enabling the king to fortify there.[41] When a bishop faces multiple enemy pawns, the defense hinges on controlling key squares to halt pawn storms, using the bishop's mobility to target weak pawns or support the king in blockading passed pawns. Elementary fortresses, such as positioning the bishop to guard promotion paths while the king opposes advancing pawns, can secure draws even against connected passed pawns. The bishop excels in open positions but struggles if pawns fixate on its color complex, emphasizing the need for active piece play to disrupt the opponent's structure. The two bishops and pawn versus lone king endgame forms a strong winning force through coordinated action, where the bishops control adjacent diagonals to restrict the enemy king and facilitate pawn promotion.[43] The attacking side maneuvers the bishops to cut off escape routes, often driving the king to the board's edge before advancing the pawn under king support. This setup leverages the bishop pair's control over both colors, making it nearly always winnable with precise play.[43] Opposite-color bishops with pawns tend to be drawish due to the bishops' inability to attack each other's pawns effectively, allowing blockades on protected squares of the opposite color.[44] The weaker side can often create a fortress by placing pawns on the color controlled by the opponent's bishop, neutralizing attacks and leading to perpetual checks or stalemates.[44] Winning requires a significant pawn majority or connected passed pawns to overcome this inherent defensive potential. The concepts of good and bad bishops relate to pawn structure harmony, where a good bishop operates on the opposite color from its own pawns, enabling it to attack enemy weaknesses without obstruction.[45] Conversely, a bad bishop is hemmed in by friendly pawns on the same color, limiting its scope and turning it into a liability in endgames.[45] Players aim to position pawns flexibly to maximize the good bishop's activity while minimizing the bad one's restrictions.Rook Endgames
Rook and Pawn vs Rook
The rook and pawn versus rook endgame is one of the most frequent and complex material imbalances in chess, often determining the outcome of games due to the rook's power in supporting or obstructing pawn promotion. In this configuration, the side with the extra pawn seeks to promote it while the defender aims to capture it or force a draw through perpetual checks, rook activity, or positional restrictions. Key theoretical positions like the Lucena and Philidor dictate whether the position is winnable or drawable, with optimal play hinging on king and rook coordination.[26] The Lucena position represents the cornerstone of winning strategy for the attacking side, where the rook shelters the king from checks to allow the pawn's advance toward promotion. Named after Luis Ramírez de Lucena (c. 1465–1530), this setup typically arises with the attacking pawn on the sixth or seventh rank and the king in front of it, opposed by the defending rook delivering rear checks. The critical technique is "bridge-building," where the attacking rook moves to the fourth rank (e.g., Rg4 in a standard diagram) to form a protective barrier, blocking checks while the king maneuvers to safety on the fifth or sixth rank. For instance, after 1. Rf4+ Ke2 2. Rg4, the rook on g4 shields the king at f5, enabling pawn promotion in a few moves despite defensive resistance. This method overcomes common defenses like the Philidor setup if executed precisely, turning a potentially drawn position into a win.[46][26] In contrast, the Philidor position provides a robust drawing resource for the defender, featuring the rook positioned behind the passed pawn on the third rank to cut off the attacking king and restrict its entry into the promotion race. Discovered by François-André Danican Philidor in 1777, it requires the defending rook to maintain activity on the sixth rank initially (e.g., Re3 to block the king at g3), preventing the attacker from gaining the seventh rank. If the pawn reaches the sixth rank, the defender shifts to rear checks or exchanges rooks only if the resulting king and pawn endgame is drawable, such as by retaining opposition. Accurate play here forces a stalemate or zugzwang on the attacker, as premature rook exchanges often lead to a lost pawn ending.[47][26] The relative placement of the rook to the pawn profoundly influences activity and outcome: a rook behind the passed pawn enhances its protection and advance (e.g., on the second rank supporting a seventh-rank pawn), often securing a win if the king provides frontal support, whereas a rook in front (e.g., on the seventh rank for the attacker) dominates by invading the defender's position and capturing loose pawns. Defensively, a rook on the seventh rank can tie down the opponent's king and rook, but it risks zugzwang if the attacker outflanks it. Rook activity rules emphasize control of the seventh rank for the superior side, as it restricts the enemy king and supports breakthroughs, while the inferior side prioritizes checks and pawn captures over passive defense.[26] With multiple pawns, the attacking side exploits pawn majorities to create passed pawns, using the rook for support in breakthroughs, such as lifting to the sixth rank to force promotion against a rook and one or two pawns. A rook and two connected passed pawns typically win if advanced beyond the defending king's influence, though exceptions arise with rook's pawns or doubled structures where the Vancura defense (rook cutting off behind the pawns) holds the draw. The rook facilitates pawn marches by preventing counterplay, turning pawn majorities into decisive advantages through coordinated king incursions.[26] Stalemate traps and zugzwang motifs frequently arise in these balances, offering drawing chances for the defender. For example, with a rook's pawn on the seventh rank, the defender can stalemate by retreating the king to the promotion square (e.g., Ka1 against Ra2), forcing a draw if the rook cannot capture safely. Zugzwang compels the attacker into concessions, such as in the Philidor where the rook must move from its cutting line, allowing king entry; conversely, the attacker uses it to outflank, as in Réti's theme where rook retreat to e2 zugzwangs the defender into passivity. These tactical elements underscore the endgame's precision demands.[26] Tablebase analysis and game statistics reveal that rook and pawn versus rook endgames are highly drawish, occurring in about 0.65% of games from a database of over four million, with approximately 53.67% ending in draws—implying a practical win rate of roughly 46% for the side possessing the pawn, though under optimal play the outcome depends on the specific position, and practical errors often tip the balance toward the superior side.[26]Rook vs Minor Piece
In rook versus minor piece endgames, the rook's long-range mobility often provides a significant advantage, particularly in open positions where it can control files and ranks to restrict the opponent's king and piece activity.[48] The rook typically outperforms a lone bishop or knight by delivering checks to disrupt coordination or force trades, but outcomes depend heavily on pawn structure and king placement.[24] Without pawns, these endings are generally drawn with accurate defense, as the minor piece can shield its king while avoiding capture.[49] Against a bishop in pawnless positions, the rook draws unless the defending king is confined to a corner of the same color as the bishop's squares, allowing the rook to deliver a series of checks and force checkmate.[50] The rook wins by driving the enemy king to the edge and exploiting the bishop's color-bound limitations, often maneuvering to cut off escape routes.[51] Historical analyses, such as those in Max Euwe's endgame studies, emphasize the rook's ability to restrict the bishop's diagonal control and trade into a winning king and pawn versus king scenario if pawns are later involved.[52] Rook versus knight endings without pawns are similarly drawn in most cases, with the knight's centralized posts enabling it to hop to safe squares and protect its king effectively.[21] The rook can separate the knight from its king through checks, potentially winning the knight if it strays too far, but precise defense keeps the knight close to avoid material loss.[53] When pawns are present, the rook's superiority shines in open positions, where it can capture isolated enemy pawns by attacking from afar while the minor piece struggles to defend multiple threats.[24] Against a bishop, the rook restricts diagonal access, often winning by promoting a passed pawn or trading favorably, except when the opponent's pawns are fixed on the bishop's color complex, limiting the rook's infiltration.[54] For instance, an active rook can check the king repeatedly to strip defenses and capture isolated pawns, advancing its own structure toward promotion.[48] In rook versus knight endings with pawns, the knight's agility in central positions allows it to contest key squares and draw if pawns are connected, as the rook cannot easily overrun a solid pawn chain supported by the knight.[21] The rook prevails against isolated pawns by forking or checking to win material, but connected passed pawns defended by the knight often force a draw, as the rook risks overextension.[53] A notable exception occurs with rook pawns (a- or h-file), where a "wrong" bishop—one unable to control the promotion square—leads to a draw, as the rook cannot force promotion against the bishop blocking the corner. Euwe's works highlight such positional draws, stressing the rook's need for active checks to avoid stalemate-like fortifications.[52]Queen Endgames
Queen and Pawn vs Queen
In queen and pawn versus queen endgames, the side with the extra pawn seeks to promote it to a second queen, leveraging the attacking queen's mobility to support the pawn's advance through checks, discoveries, and coordination with the king, while the defender aims to capture the pawn or force perpetual checks.[55] The queen's power allows for rapid pawn promotion if the pawn reaches the sixth or seventh rank without immediate opposition, but the defender's queen can often deliver perpetual checks from a distance, creating drawing chances unless the attacking king is active.[55] When supporting a passed pawn, the attacking queen typically centralizes to restrict the enemy king and deliver checking sequences that force the defender's king away from the pawn's path, as seen in positions where the queen moves to the sixth rank to cut off the king and enable pawn promotion.[55] For instance, with a central or knight's pawn (e.g., e- or g-pawn), the attacker wins by maneuvering the king to support the pawn while the queen checks to gain tempos, avoiding stalemate traps common with rook's pawns (a- or h-pawns).[56] Discoveries, where the queen moves reveal a check from the king or pawn, are crucial for accelerating promotion, particularly if the pawn is on the fifth rank or beyond.[55] The defending queen counters by gaining opposition to the attacking king, positioning to capture the pawn directly or initiate perpetual attacks that prevent coordinated support.[55] If the defending king reaches a drawing zone—such as the corner for rook's pawns (e.g., h8 for an h-pawn) or the southeast squares (g1, h1, g2, h2) for knight's pawns—the position often simplifies to a draw via stalemate or insufficient material after pawn capture.[56] Perpetual checks from the seventh or eighth rank are a primary defensive resource, especially when the pawn is not far advanced, as the queen's range allows it to harass the attacking king indefinitely without risking pawn loss.[55] With multiple pawns, the attacking side benefits from connected central pawns (e.g., f- and g-pawns), which are harder for the lone queen to contain, as the queen must overextend to block promotion paths, potentially leading to counterplay or material loss if the defending king is cut off.[57] However, pawn storms on the flank (e.g., h- and g-pawns) favor the defender if the attacking king lags behind, allowing the queen to pick off isolated pawns while maintaining checks.[57] The queen's versatility enables it to stop multiple passed pawns in open positions, but overextension—such as straying too far from its king—can result in defeats if the attacker forces an exchange into a winning pawn endgame.[55] A pivotal key position arises when the attacking queen occupies the sixth rank in front of the passed pawn, blocking the defending king's access and creating zugzwang, often forcing promotion in 20-50 moves with best play.[55] For rook's pawns, the defender draws by reaching the promotion corner, where queen checks lead to stalemate after pawn capture.[56] Drawing resources include fortress setups, where the defending king and queen form an impregnable barrier around a corner or edge, preventing pawn progress without allowing captures, particularly effective against rook's or bishop's pawns.[56] Insufficient material after an exchange (e.g., if the pawn is captured without promotion) also leads to draws, though rare in precise play.[55] Tablebase analyses, such as those from endgame databases, reveal that while many positions are drawn with accurate defense—especially if the pawn is on the fourth rank or earlier—the side with the pawn achieves wins in the majority of cases when the pawn reaches the sixth rank, often requiring 30-50 moves or more to force promotion against optimal resistance.[55]Queen vs Rook and Combinations
In queen versus rook endgames without pawns, the queen's superior mobility generally allows the stronger side to win by forcing the rook away from its king through systematic checks and zugzwang, though the defense can prolong the game significantly due to the rook's checking potential.[58] The primary tactics involve forks and skewers, where the queen attacks both the rook and king simultaneously or pins the rook against the king, often culminating in capturing the rook after driving the enemy king to the board's edge.[59] For instance, the queen can restrict the rook's safe squares by occupying key files or ranks, compelling it to move to vulnerable positions like light or dark squares that enable decisive checks.[58] When a pawn accompanies the rook, the queen typically captures it if isolated, then reverts to standard tactics against the rook, but connected or passed pawns on the rook's side can resist by shielding the rook or creating counterplay through promotion threats.[59] The queen's advantage lies in its ability to infiltrate and eliminate the pawn while maintaining pressure on the rook, though precise coordination is required to avoid stalemates or perpetual checks from an active rook defending the pawn structure.[58] Against a rook and minor piece, the queen faces coordination challenges from the opponent's pieces, which can support each other to contest key squares, yet the queen usually prevails unless the defense establishes a fortified position where the minor piece blocks invasion routes.[59] Drawing resources for the inferior side include maximizing rook activity to generate perpetual checks or force stalemates, particularly if the minor piece (bishop or knight) creates a blockade that the queen cannot dismantle without losing tempo.[58] In positions involving pawns on both sides, the queen's edge in promoting passed pawns often secures victory, but the rook can counter by dominating the seventh rank to restrict the enemy king and queen while supporting its own pawns.[59] José Raúl Capablanca analyzed several theoretical examples illustrating these dynamics in queen vs. rook endgames, emphasizing tactics to drive the rook from defending the king.[58]Complex Material Endgames
Multiple Minor Pieces vs Rook
In endgames featuring two bishops against a rook, without pawns, the position is generally a theoretical draw with optimal play, though the bishops can secure a win in specific positions by restricting the rook's mobility and driving the enemy king toward a corner. The bishops coordinate along long diagonals to limit the rook's access to key squares, often forcing it into a passive role or trapping it for capture in those winning scenarios. Draws are the norm in such pawnless positions, occurring in the majority of cases, with wins requiring exceptional placement such as in variants of the Philidor position. The bishop and knight versus rook endgame presents greater complexity due to the pieces' differing movement patterns, but without pawns, it is generally a draw, though wins are possible if the rook is trapped or the defending king is vulnerable near a corner. It remains favorable for the minor pieces side, particularly when pawns are present to create mate threats or support promotion. The knight's ability to control central squares complements the bishop's diagonal reach, allowing threats against the rook or king that the lone rook struggles to counter effectively. With pawns, tablebase analysis confirms most positions as winnable for the minor pieces with optimal play.[60] Endgames with three minor pieces against a rook are overwhelmingly winning for the side with the extra material, as the combined firepower overwhelms the rook's defensive capabilities. Configurations involving two bishops and a knight prove especially potent, enabling rapid king hunts or pawn advances, though knight-heavy setups (such as three knights) can lead to draws if the rook centralizes and avoids entrapment. Tablebases for five-piece variants, including pawns, classify the majority of such positions as wins, with distances to victory often under 30 moves when the minor pieces control open lines.[60] When pawns enter the equation, multiple minor pieces excel at supporting pawn promotion while countering the rook's attempts to infiltrate or create counterplay through checks and pawn hunts. The minor pieces' versatility allows them to shield passed pawns and restrict the rook's activity, often turning connected pawns into queens despite the rook's checking distance. This imbalance favors the minor pieces side in most middling pawn structures, as the rook alone cannot match their collective control over promotion paths. Central motifs in these endgames include the minor piece battery, where two bishops align on a diagonal to exert doubled pressure on the rook or a key pawn, amplifying threats and forcing concessions. Rook trapping is another key theme, employing the minor pieces and king to confine the rook to an edge or corner, where it becomes vulnerable to capture or material loss—often executed by maneuvering knights to block escape routes alongside bishop pins. These tactics underscore the minor pieces' superiority in coordination over the rook's linear power.Piece vs Multiple Pawns
In chess endgames, positions where a single piece opposes multiple pawns present complex challenges, often hinging on the piece's ability to capture or blockade advancing pawns while avoiding stalemate or zugzwang. The outcome depends on pawn connectivity, advancement, and king support, with the piece typically dominating isolated or backward pawns but struggling against coordinated passed pawns. These scenarios emphasize precise calculation to prevent promotion, as even a single pawn breakthrough can decide the game.[61] Rook versus multiple pawns favors the rook when pawns are isolated or separated, allowing it to pick them off from afar or behind while the defending king struggles to coordinate. However, against connected passed pawns—especially if advanced to the fifth or sixth rank—the rook often loses, as the pawns can promote under mutual support before the rook intervenes effectively. For instance, two connected pawns on the sixth rank with the king nearby draw or win against the rook, per tablebase analysis, while the rook prevails if both pawns remain on the fifth rank or lower without full king aid. Müller and Lamprecht detail these thresholds in their comprehensive treatment, noting that three or more pawns require the rook to prioritize king checks to disrupt the pawn mass.[61][62] Minor pieces against multiple pawns rely on blockade rather than capture, with bishops and knights excelling in containment but vulnerable to unsupported pawn advances. A bishop can halt pawns on the same color complex by controlling key diagonals, but multiple passed pawns on opposite colors overwhelm it, as seen in scenarios where four or more pawns push forward, forcing the bishop to sacrifice itself or allow promotion. Knights, being slower, blockade effectively against one or two pawns by occupying promotion squares (e.g., three key squares for central pawns), drawing if positioned accurately ahead of the pawn; against multiple pawns, however, they falter if the pawns gain tempo or the enemy king supports the advance. In both cases, the minor piece loses if pawns reach the seventh rank without opposition.[63][64] Queen versus a pawn mass grants the queen vast mobility to capture isolated pawns or check the king into passivity, often winning against up to seven pawns if they lack connectivity or king protection. Yet, overcommitment risks stalemate or pawn breakthroughs, particularly with advanced connected pawns on the queenside, where the queen may need to sacrifice material to halt promotion. Tablebases confirm the queen triumphs in most configurations unless pawns form an impregnable chain on the seventh rank.[65] Fortress draws arise when pawns form impenetrable walls, restricting piece infiltration despite material inferiority; a rook or minor piece may dominate open space but cannot breach a compact pawn structure supported by the king, leading to perpetual blockade. Classic examples include three locked pawns on the second rank versus a rook, where the rook's activity is neutralized without forcing gains.[66] In pawn races, piece interference resolves tensions by blocking promotion paths or capturing en route, tipping the balance; for example, a rook or queen can interpose to delay one pawn while the king captures another, often securing a win if the interference gains a tempo. Connected pawns amplify this dynamic, as the piece must prioritize the faster passer. Müller and Lamprecht's studies illustrate these themes through practical examples, such as rook versus three pawns where tactical interference forces a draw, underscoring the need for exact play in unbalanced material.[62]Computational and Theoretical Advances
Role of Tablebases
Tablebases, also known as endgame databases, are precomputed repositories of all possible chess positions involving a limited number of pieces on the board, providing exact evaluations and optimal moves for perfect play by both sides.[67] These databases have revolutionized the study of chess endgames since their inception in the 1980s, enabling precise analysis that surpasses human capabilities in complexity and depth.[68] The development of tablebases began with early efforts in the 1970s and 1980s, but significant progress occurred in the late 1990s with Eugene Nalimov's creation of compressed databases. Nalimov's tablebases, completed for up to six pieces by the early 2000s—with the full six-piece set finalized around 2005—totaled approximately 1.2 terabytes and marked a milestone in accessibility for chess software.[69] Building on this, the Lomonosov tablebases, developed by a team at Lomonosov Moscow State University and released starting in 2012, provided the first full 7-piece set, probeable online via ChessOK. Independently, Ronald de Man's Syzygy tablebases introduced in 2013 for six pieces and extended to seven pieces in 2018 offered more efficient compression, reducing storage needs while maintaining full accuracy for outcomes under the fifty-move rule.[70][71] Tablebases are generated through retrograde analysis, a process that starts from terminal positions—such as checkmates or draws by stalemate—and works backward to assign values to all reachable positions. This method computes the exact outcome (win, loss, or draw) for each position assuming optimal play, along with metrics like the number of moves to mate (DTM) or to a pawn move or capture (DTZ), and identifies the best move by evaluating all legal options.[67] The resulting databases store this information in a highly compressed format, allowing rapid probing during analysis or gameplay. As of 2025, seven-piece tablebases like Lomonosov and Syzygy remain the most comprehensive fully available sets, with sizes around 15-18 terabytes for the complete collections, accessible online via platforms such as Lichess and ChessOK for real-time queries.[60][71] Efforts on eight-piece tablebases continue, led by researchers like Marc Bourzutschky, who have generated partial databases covering pawnless endgames and estimating total sizes exceeding 500 terabytes for subsets, though full completion remains resource-intensive and not yet publicly distributed in the same manner as prior sets.[72] The influence of tablebases on endgame theory has been profound, debunking long-held myths and revealing counterintuitive results that refine classical understandings. For instance, tablebases have shown that certain positions previously analyzed as draws by human experts are actually winnable with precise play, such as in complex minor-piece endgames where optimal defense was underestimated; in the case of two knights versus a pawn, tablebases confirm wins in more configurations than early theory suggested, particularly when the pawn is blockaded effectively, overturning assumptions of near-impossibility in many scenarios.[68] These discoveries have corrected erroneous studies and expanded practical endgame knowledge, with examples like a mate in 90 moves in queen-and-knight versus rook-and-minors highlighting the depth required for forced wins.[68] Despite their power, tablebases face significant limitations for endgames with nine or more pieces, as the number of possible positions explodes exponentially—reaching on the order of 10^20 for nine pieces—rendering full computation and storage impractical with current technology due to prohibitive requirements for processing power, memory, and disk space.[67] Modern chess engines, such as Stockfish, integrate tablebase probing seamlessly, with support for Syzygy databases added since 2016 to enhance endgame evaluation and move selection when the position reduces to seven or fewer pieces, allowing the engine to retrieve perfect play directly from the database.[73]Longest Known Forced Wins
In chess endgames, the longest known forced wins are determined by endgame tablebases, which compute the optimal number of moves to victory under perfect play. As of 2025, the record for the longest forced mate in a 7-piece endgame, ignoring the 50-move rule, is 549 moves in a position with king, queen, and pawn versus king, rook, bishop, and knight (KQP vs. KRBN). This position requires White to promote the pawn to a knight before embarking on an extended sequence of maneuvers to force checkmate.[74][75] Historical progression of these records has shown steady increases with computational advances. For 6-piece endgames, the longest known forced win was 115 moves in two knights versus a pawn, a configuration notorious for its zugzwang requirements and king opposition challenges. The 7-piece milestone in 2018, via the Syzygy tablebases generated by Ronald de Man and Bojun Guo, extended this to the 549-move record, highlighting configurations like KQP vs. KRBN where pawn promotion leads to intricate piece interactions. Recent partial computations for 8-piece endgames, as of August 2025, have identified winning lines up to 400 moves to conversion (depth-to-capture) in pawnless setups, though full mate distances remain under exploration and are expected to exceed 7-piece maxima without bound.[70][72] These protracted wins often arise in complex material imbalances, such as a rook and multiple pawns versus minor pieces like a bishop and knight (e.g., KRPP vs. KBN), where the winning side must execute precise king maneuvers to restrict the opponent's pieces while advancing pawns without allowing counterplay. Zugzwang chains are critical, forcing the defender into positions where any move weakens their setup, but the attacker must avoid sequences exceeding the 50-move rule to claim a practical win. For instance, in Syzygy databases, a representative 7-piece position might involve White's rook supporting advanced pawns against Black's bishop and knight, requiring up to 72 moves to force a pawn promotion or capture that zeros the move counter, preventing a draw claim. Such examples underscore the theoretical depth, as tablebases reveal paths that sacrifice immediate progress for 50-move compliance.[60][76] The implications for endgame study are profound, emphasizing patience and long-term planning in practical play. Players facing these positions must recognize that human intuition often underestimates the required precision, leading to unnecessary draws or losses; tablebase access in engines like Stockfish has revolutionized training by allowing exploration of these extremes. These records also inform theoretical advances, as longer wins test computational limits and refine metrics like DTZ50 (distance to zeroing the 50-move counter), ensuring wins are enforceable under tournament rules.[70][77]Endgame Analysis and Statistics
Classification Systems
Chess endgames are systematically classified to facilitate study, analysis, and database organization, primarily by the material balance on the board and the types of pieces involved. These systems enable players, authors, and software developers to reference specific configurations efficiently, such as pawnless endings versus those with pawns. Early classifications focused on practical groupings for instructional purposes, while modern approaches incorporate computational metrics for precision.[78] One foundational historical system appears in Reuben Fine's 1941 book Basic Chess Endings, which organizes endgames into broad categories based on piece types and complexity. The table of contents divides content into elementary mates (e.g., queen vs. king, rook vs. king, two bishops vs. king), king and pawn endings, pure rook endings, rook and pawn endings, endings with minor pieces, queen endings, and composite endings involving multiple pieces. This structure emphasized frequently occurring practical positions, providing rules and examples without exhaustive computation, and served as a reference for decades. In contrast, modern classification systems extend this categorical approach with more granular coding, akin to the Encyclopaedia of Chess Openings (ECO) codes but tailored to endgames. The Encyclopaedia of Chess Endings (ECE), published by Chess Informant starting in 1982, employs a hierarchical system prioritizing the "most valuable" piece present, such as queen endings (Q1–Q10), rook endings (R1–R10), bishop endings (B1–B4), knight endings (N1–N3), and pawn endings (P1–P5). Subcategories further divide by material imbalances, like R + P vs. N for rook and pawn versus knight, allowing systematic indexing of thousands of positions across volumes. This framework supports both theoretical exploration and practical application in literature.[79] A key notational convention for labeling endgames, often associated with grandmaster John Nunn's works and widely adopted in computational tools, uses abbreviated piece symbols to denote configurations. For instance, KQKR represents king and queen versus king and rook (with kings implied), while KRPKN indicates king and rook plus pawn versus king and knight. This compact notation, omitting pawns unless specified, standardizes references in books like Nunn's Secrets of Rook Endings (1992) and endgame tablebases, enabling quick identification of material symmetries or imbalances. Computational advances have introduced metrics like Depth to Zeroing (DTZ), which measures the number of half-moves to a "zeroing" event—typically a pawn move, capture, or checkmate—that resets the 50-move draw rule. In tablebases such as Syzygy or Nalimov, DTZ prioritizes practical outcomes under tournament rules over shortest paths to mate, contrasting with Depth to Mate (DTM). For example, in KQKR positions, DTZ values guide engines to force a win in an average of 28.7 moves for White, accounting for optimal defense. This metric enhances classification by adding a temporal dimension to win/draw/loss outcomes.[67][80] Tablebases provide empirical win, draw, and loss percentages for classified endgames, revealing theoretical equilibria in common setups. In 3- to 7-piece positions, White wins approximately 40.1% of the time with optimal play, draws occur in 13.6%, and Black wins 46.4%, though these skew due to the side to move; for specific cases like KQ vs. KR, White secures a win in 99.0% of positions, with draws at 0.8% and losses at 0.2%. Similarly, in KBP vs. KN (king, bishop, and pawn vs. king and knight), wins for the stronger side reach 82.3%. These statistics, derived from exhaustive enumeration, inform classifications by highlighting drawable fortresses or forced wins previously underestimated.[81][82] Such systems find practical use in chess literature and software for rapid reference and training. Books like the ECE volumes and Nunn's endgame series organize chapters by these labels, allowing readers to target weaknesses, such as rook endings (R3–R7). In software like Lichess or ChessBase, classifications enable querying tablebases for DTZ-optimal moves or generating drills, streamlining preparation for over-the-board play. This integration bridges theory and practice, with notations serving as universal shortcuts in databases exceeding trillions of positions.[83] Prior to tablebases, classifications relied on human analysis, leading to gaps now corrected computationally. For instance, the bishop versus knight endgame was often assumed drawable in pawnless positions, but tablebases confirm it as a general draw only under optimal play, while certain pawn configurations reveal subtle wins; more dramatically, two bishops versus a knight—long considered a draw—was reclassified as a win in most cases, requiring up to 66 moves, overturning pre-1980s assumptions in works like Fine's. These revisions have refined ECE-like systems, ensuring modern classifications reflect verifiable perfection.Frequency of Endgame Types
Statistical analysis of large chess databases reveals that endgames occur in approximately 60% of all games, with rook endgames being the most prevalent type, accounting for 8–10% of total games or roughly 40% of all endgames reached.[84] Pawn-only endgames, in contrast, appear in about 3% of games, or around 20% of endgames.[84] These figures are derived from mega-databases such as the ChessBase Mega Database, which as of 2025 encompasses over 10 million master-level games, showing consistent dominance of rook configurations due to their frequency in late middlegames.[85] The following table summarizes the top 10 most common endgame types by occurrence percentage in games, based on an analysis of over 500,000 master games from the early 2000s; modern databases indicate similar proportions with slight increases in complex variants.[86]| Rank | Percentage | White Material | Black Material |
|---|---|---|---|
| 1 | 8.45% | Rook | Rook |
| 2 | 6.76% | Rook + Bishop | Rook + Knight |
| 3 | 3.45% | Two Rooks | Two Rooks |
| 4 | 3.09% | Rook + Pawn | Rook |
| 5 | 2.81% | Rook | Rook + Pawn |
| 6 | 2.74% | Rook + Two Pawns | Rook |
| 7 | 2.43% | Rook + Pawn | Rook + Pawn |
| 8 | 1.68% | Rook + Bishop | Rook |
| 9 | 1.59% | Rook + Knight | Rook |
| 10 | 1.53% | Rook + Two Pawns | Rook + Pawn |