Fact-checked by Grok 2 weeks ago

Starting pitcher

In baseball, a starting pitcher, also known as a starter, is the pitcher who begins the game for their team by delivering the first pitch and is credited with a game started solely for being the initial hurler, regardless of innings pitched.^[1] Typically, they are expected to pitch five or more innings to remain eligible for a win, though conventions often aim for six or more to provide a "quality start" by limiting earned runs to three or fewer while conserving bullpen resources.^[1]^[2] This role demands exceptional stamina, control, and a diverse repertoire of pitches—usually three or more—to face the opposing lineup multiple times and dictate the game's early pace.^[2] The starting pitcher forms the cornerstone of a team's pitching strategy, operating within a rotation of four or five pitchers who alternate starts every four to five days to balance workload and recovery.^[2] Their performance profoundly impacts outcomes, as effective starters limit runs and enable offensive opportunities, with historical data showing teams succeeding more when their rotations excel.^[3] In Major League Baseball (MLB), aces like Greg Maddux exemplified this through efficient dominance, such as his 13 "Maddux" complete-game shutouts on fewer than 100 pitches since 1988.^[2] Historically, the role evolved from 19th-century ironmen who completed nearly all games—such as George Bradley's 63 complete games in 64 starts in 1876—to modern limits driven by injury prevention and analytics.^[4] Early eras featured pitchers logging over 400 innings annually, but by the 2000s, averages dropped below 260 due to five-man rotations, pitch-count caps around 100, and strategies like the "opener" tactic introduced in 2018, where a reliever starts briefly before a bulk pitcher follows.^[1]^[4] Today, amid debates over deepening starts to counter bullpen overuse, the position remains vital, with elite rotations like the 1998 Atlanta Braves—featuring three future Hall of Famers—highlighting its potential to drive championships.^[2]^[5]

Definition and Role

Core Definition

In baseball, a starting pitcher is the player who initiates the game for their team by delivering the first pitch from the mound and is responsible for pitching the opening innings until replaced, typically aiming to cover 5 to 7 innings to establish early control.^[6]^[1]^[7] This role demands endurance and strategic depth, as the starter must manage the game's pace and limit scoring opportunities in the initial phases. Distinct from relief pitchers, who enter subsequent innings to preserve leads, handle high-leverage situations, or finish games after the starter's removal—often due to pitch count limits, fatigue, or performance— the starting pitcher focuses on dictating the contest's early momentum and influencing the overall strategy.^[8]^[9] Within a team's pitching staff, starting pitchers operate in a structured rotation, where each is scheduled to pitch once every 4 to 5 days, allowing time for physical recovery and preparation while ensuring consistent coverage across the season's 162 games.^[6] This system typically involves five starters per team, balancing workload to sustain performance throughout the long schedule.

Responsibilities in Games

The starting pitcher assumes the mound at the beginning of the game, delivering the first pitch to the opposing team's leadoff batter and setting the tone for the contest. This role involves managing the early innings by establishing command of the strike zone, inducing weak contact, and minimizing baserunners to preserve the team's defensive posture. To sustain performance throughout their outing, starters must conserve energy, pacing their effort across pitches and innings to handle the physical demands of throwing 100 or more pitches at high velocity.^[6]^[10] Strategically, starting pitchers adjust their approach based on the game score, opting for aggressive strikes when leading or mixing pitches more conservatively in close contests to limit damage. They face the opposing lineup two to three times per outing, requiring adaptation to hitters' adjustments by varying pitch location and type to exploit weaknesses identified in prior at-bats. Close coordination with the catcher is essential for pitch sequencing, where signals and mound visits guide selections that disrupt batter timing and prevent patterns from emerging.^[11] Key decision points include evaluating whether to pitch around dangerous hitters or issue an intentional walk, particularly in high-leverage situations such as with runners in scoring position and a potent batter at the plate. These choices hinge on the immediate game context, weighing the risk of a big hit against loading the bases for a less threatening follow-up batter, thereby influencing the inning's outcome without escalating unnecessary pressure.^[12]^[11]

Historical Development

Origins in Early Baseball

The role of the starting pitcher emerged in the mid-19th century as baseball transitioned from informal recreational play to organized competition, with pitchers initially delivering the ball underhand from a distance of 45 feet under the rules established by the National Association of Base Ball Players in 1857.^[13] This underhand style limited velocity and movement, emphasizing control and endurance over power, as pitchers were expected to deliver every pitch in a game without relief options due to the era's small team rosters of typically 9 to 11 players.^[14] Early pitchers like William "Candy" Cummings exemplified this foundational role; in 1867, while playing for the Brooklyn Excelsiors, Cummings is credited with inventing the curveball by experimenting with wrist snaps inspired by seashells, first debuting it effectively against Harvard University on October 7 of that year.^[13] This innovation introduced deception to pitching, allowing starters to outmaneuver batters and establish dominance in games that often lasted hours.^[15] The establishment of professional leagues solidified the starting pitcher's centrality. The National League, founded on February 2, 1876, by William Hulbert and other club owners, marked the first major professional circuit, where pitchers like Albert Spalding of the Chicago White Stockings routinely started and completed nearly every game, pitching over 400 innings in a season.^[16] With no specialized relief pitchers and schedules expanding to around 60-70 games per team, a single dominant starter often handled 50 or more contests, as seen with Cummings himself leading the league in games pitched with 48 appearances for the Hartford Dark Blues in 1875 under the preceding National Association.^[14] This structure prioritized stamina, with complete games the norm—pitchers like Tommy Bond completed 386 of 408 starts between 1874 and 1884—reflecting the lack of roster depth and the game's emphasis on individual endurance.^[14] A pivotal shift occurred in 1884 when the National League amended its rules to permit overhand deliveries for the first time, allowing pitchers to raise their arms above the shoulder and increasing ball speed and variety.^[17] This change, debated for favoring pitchers over hitters, transformed the starting role; Charles "Old Hoss" Radbourn of the Providence Grays exploited it masterfully, starting 73 games and winning a record 59 that season while pitching 678 two-thirds innings, often on short rest.^[17] The transition from underhand to overhand thus elevated the starter's strategic importance, setting the stage for the position's evolution while maintaining the expectation of completing most outings amid limited team resources.^[14]

Evolution in Modern Era

The role of the starting pitcher began to evolve significantly in the early 20th century, beginning in the 1900s with the rise of relief pitching, as rule changes like the foul strike rule—introduced in the National League in 1901 and the American League in 1903—increased the demands on pitchers and prompted managers to pull starters more frequently when facing trouble.^[18]^[19] This shift marked a departure from the expectation of complete games, with relief appearances spiking notably in that decade; for instance, pitchers like Doc Crandall and Dave Danforth emerged as early specialists, logging multiple high-leverage outings that influenced strategic flexibility.^[18] Eddie Cicotte, a prominent starter for the Chicago White Sox, exemplified the era's versatility by occasionally relieving while mastering deceptive pitches like the shine ball, contributing to the broader adaptation of bullpen usage amid growing offensive pressures.^[20] Following World War II, the decline of complete games accelerated with the specialization of bullpens, as managers increasingly relied on dedicated relievers to preserve leads rather than expecting starters to finish what they began.^[21] By the 1960s, the percentage of starts ending in complete games had fallen to 25%, a stark contrast to earlier decades, driven by the emergence of relief aces like Hoyt Wilhelm, who amassed 228 career saves with a 2.52 ERA, and Jim Konstanty, the 1950 National League MVP primarily for his relief work (22 saves, 2.66 ERA).^[21] This specialization allowed starters to focus on early-game dominance but shortened their outings, as seen in strategies employed by managers like Casey Stengel, who deployed pitchers such as Allie Reynolds in hybrid roles to optimize matchups.^[21] In the post-1970s era, the introduction of the designated hitter (DH) rule in the American League in 1973 further altered pitching strategies by removing the need for pitchers to bat, which reduced late-inning pinch-hitting decisions and enabled managers to keep starters in longer against offenses but also heightened overall run production, pressuring pitchers to perform more efficiently.^[22] This rule created league disparities, with AL games seeing elevated scoring that influenced pitching approaches, such as emphasizing strikeouts over ground-ball inducement to counter the DH's offensive boost.^[23] These disparities ended in 2022 when Major League Baseball adopted the designated hitter universally, standardizing rules and continuing to shape pitching strategies by eliminating the need for National League pitchers to bat.^[24] During the 1990s steroid era, pitchers responded to rampant performance-enhancing drug use among hitters—leading to unprecedented home run surges—by increasing average fastball velocity from around 90 mph to over 91 mph and incorporating greater pitch variety, including more sliders and changeups, to neutralize power threats.^[25]^[26] Entering the 21st century, analytics-driven strategies have dramatically shortened starting pitchers' outings, with the average innings per start dropping from approximately 6.5 in the 1990s to under 5.5 by the 2020s, as teams prioritize pulling starters after 15-18 outs to leverage bullpen matchups and maximize run prevention.^[27]^[28] This trend reflects data-informed decisions emphasizing pitcher fatigue curves and platoon advantages, reducing complete games to near rarity (less than 1% of starts in recent seasons).^[29] The 2023 introduction of the pitch clock, mandating 15 seconds between pitches with bases empty (20 with runners on), has accelerated game pace by about 13% without significantly altering outing lengths for starters but intensifying focus on efficient pitch selection amid faster rhythms.^[30]^[31]

Pitching Fundamentals

Mechanics and Delivery

The mechanics and delivery of a starting pitcher encompass the coordinated sequence of body movements designed to propel the baseball toward home plate with optimal velocity, accuracy, and deception. This process is fundamentally biomechanical, relying on the efficient transfer of kinetic energy from the lower body through the core and upper extremities to the throwing arm. Proper form not only enhances performance by maximizing pitch speed and command but also mitigates injury risk by distributing stress across multiple muscle groups rather than overloading the elbow or shoulder. Starting pitchers typically employ one of two primary delivery positions: the windup or the stretch. The windup, used when runners are not on base, begins with the pitcher facing the batter and pivoting on the rubber to initiate a leg lift, allowing for a full-body wind-up that generates greater momentum and velocity—often reaching up to 95 mph or more for elite fastballs. In contrast, the stretch position, adopted with runners on base, involves a quicker, more abbreviated motion starting from a sidearm stance with hands at the belt, which reduces the time to first pitch and holds runners closer to base but may sacrifice some power due to the compact stride. Both deliveries progress through distinct phases: the arm cocking phase, where the throwing arm extends backward as the front leg strides forward; the arm acceleration phase, marked by rapid internal rotation of the humerus; and the deceleration phase, where the arm slows post-release to absorb forces. A critical element in this sequence is hip-shoulder separation, the angular difference between the hips (which rotate first toward the plate) and the shoulders (which follow with a delay), which can contribute approximately 80% of the total kinetic chain energy transfer for increased velocity.^[32] The follow-through completes the motion, with the throwing arm crossing the body and the back leg pulling forward to maintain balance and prevent torque on the rotator cuff. Key principles underpinning effective mechanics include balance, timing, and release point consistency. Balance is achieved through a stable center of gravity during the stride, with the lead foot landing squarely and the head remaining over the midline to avoid over-rotation that could compromise control. Timing synchronizes the lower-body drive with upper-body rotation, ensuring peak hip velocity precedes shoulder velocity for optimal energy transfer. Release point consistency—maintaining the ball's exit from the hand at a uniform height and depth, typically around 6 feet from the ground and 55 feet from the plate—enhances command by minimizing variability in pitch location; MLB pitchers typically exhibit release point standard deviations of 1-2 inches, correlating with improved strike zone command. As a baseline, fastball grips often involve a two-seam or four-seam hold with fingers across or along the seams to promote backspin and stability, setting the foundation for command before introducing variations. Since the implementation of the pitch clock in 2023, pitchers must adhere to time limits between deliveries (15 seconds with no runners, 20 seconds with runners on base), which standardizes tempo but limits extreme variations. For starting pitchers, who must sustain performance over multiple innings, mechanical adjustments focus on preserving arm efficiency and unpredictability. Building arm strength progressively involves maintaining stride length (ideally 80-90% of pitcher height) and trunk flexion to leverage core power without early fatigue, allowing velocity to hold steady through the fifth inning or beyond in professional play. Varying delivery elements, such as subtle changes in leg lift height or arm slot angle (e.g., from overhand to three-quarters), disrupts hitters' timing without tipping pitches, as long as telltale signs like head movement or grip exposure are avoided. These adaptations ensure the starter remains effective as a game's anchor while adhering to biomechanical ideals.

Pitch Types and Arsenal

A starting pitcher's arsenal typically consists of a mix of fastballs and off-speed pitches designed to generate swings and misses, weak contact, or ground balls. The core pitches include the four-seam fastball, which is thrown with backspin for a straight trajectory that can create an optical rising effect; as of 2024, typical velocities for major league starters range from 93-98 mph. In contrast, the two-seam fastball, often referred to as a sinker, features arm-side run and downward movement due to its grip, with similar velocities around 91-96 mph, making it effective for inducing ground balls. Off-speed options like the curveball provide significant vertical drop with topspin, thrown at 75-85 mph to disrupt timing, while the slider offers lateral and downward break at 82-90 mph, bridging the gap between fastball speed and breaking ball movement. The changeup mimics fastball arm action but arrives 8-10 mph slower, around 82-92 mph, with potential fade to exploit velocity deception. Additional pitches such as the cutter, a harder variant of the slider with late glove-side cut at 88-94 mph, and the sinker variant of the two-seamer, enhance versatility by adding subtle movement profiles.^[33] Building an effective arsenal involves assembling 4-5 complementary pitches that maximize deception through varied movement and velocity, differing from relief specialists who often rely on 2-3 high-leverage offerings. Starting pitchers prioritize a balanced mix, such as a primary fastball paired with breaking balls and an off-speed pitch, to keep hitters off-balance across multiple innings. A key strategy is pitch tunneling, where pitches share a similar initial trajectory from the release point—often up to 20-25 feet toward the plate—before diverging, delaying batter recognition and increasing swing-and-miss rates.^[34] For instance, a four-seam fastball elevated in the zone can tunnel effectively with a low curveball, creating visual similarity in early flight. This approach relies on consistent mechanics to maintain repeatable release points, allowing the arsenal to function as an interconnected system rather than isolated pitches.^[34] Pitch selection within the arsenal is influenced by factors like batter handedness, weaknesses, and count situations to optimize outcomes. Against same-handed batters (platoon disadvantage), pitchers often favor breaking balls like sliders or curveballs to exploit movement away from the barrel, while opposite-handed matchups (platoon advantage) lean toward fastballs or sliders for early-count aggression. To target weaknesses, a starter might deploy changeups against power hitters prone to chasing low-and-away pitches or sliders to contact-oriented batters struggling with lateral break. In count situations, fastballs dominate ahead (e.g., 0-2) to finish at-bats, whereas behind counts (e.g., 2-0) shift toward off-speed pitches to avoid the heart of the zone and climb back into favorable positions. Left-handed specialists, though more common in relief roles, illustrate handedness extremes by emphasizing cutters or sliders that dart away from right-handed hitters.^[35]

Performance and Management

Workload Considerations

Starting pitchers in Major League Baseball (MLB) typically operate within a standard five-man rotation, where each pitcher starts every fifth game, providing four to five days of rest between outings to allow for recovery and preparation.^[36] This structure emerged as the norm in the late 20th century to manage fatigue and sustain performance over a 162-game season, with adjustments occasionally made for factors such as cross-country travel, which can induce jet lag and impair pitching effectiveness, or weather conditions that might delay games and alter the rotation sequence.^[37]^[38] Historically, starting pitchers were expected to deliver six or more innings per start to secure wins and minimize bullpen usage, a benchmark rooted in eras when complete games were common and workloads exceeded 200 innings annually.^[39] In the modern game, particularly since the 2010s, advanced analytics have shifted priorities toward quality over quantity, emphasizing efficient outings that preserve pitcher velocity and command while reducing exposure to fatigue, even if it means fewer innings.^[40] Teams monitor workloads primarily through pitch counts, with a common threshold of around 100 pitches per start to prevent diminished performance and overexertion, though this limit is applied flexibly based on real-time effectiveness.^[41] Average innings per start have declined accordingly, from approximately 6.0 in 2000 to about 5.5 in the 2020s, reflecting broader strategies to optimize health and longevity amid increased pitch velocity and specialized bullpens.^[27]^[42]

Injury Prevention Strategies

Starting pitchers in Major League Baseball (MLB) commonly face overuse injuries to the elbow and shoulder due to the repetitive high-stress nature of their role. Ulnar collateral ligament (UCL) tears, often requiring Tommy John surgery, have surged since the 1990s, affecting approximately 36% of active MLB pitchers as of 2025.^[43] Rotator cuff strains are a common shoulder injury among pitchers.^[44] Shoulder impingement, resulting from improper arm positioning during the pitching motion, further contributes to these issues by increasing joint stress.^[45] Injury prevention emphasizes targeted training and screening to address biomechanical vulnerabilities. Strength training programs focusing on core stability and scapular muscles help mitigate UCL strain and shoulder overload by enhancing the kinetic chain's efficiency.^[46] Biomechanics screening, such as motion capture analysis, identifies flaws like excessive shoulder horizontal adduction or inadequate stride length, allowing corrections that reduce elbow torque by up to 20-30% in optimized deliveries.^[45] Offseason conditioning programs, exemplified by those from Driveline Baseball, incorporate personalized strength and explosiveness drills alongside lab-based assessments to build durability and prevent fatigue-related breakdowns.^[47] Recovery protocols prioritize structured rehabilitation and monitoring to restore function safely. Following Tommy John surgery, pitchers typically undergo 12-18 months of rehab, including phased strengthening and gradual throwing progression under medical supervision.^[48] In minor leagues, pitch count ramps adhere to MLB's Pitch Smart guidelines, limiting outings to 75-95 pitches per game for younger athletes to curb overuse and allow adequate rest periods of 4-7 days based on volume.^[49] Sports medicine teams monitor fatigue through tools like the acute:chronic workload ratio (ACWR), where ratios exceeding 1.5 signal elevated injury risk, enabling interventions such as session rating of perceived exertion (sRPE) assessments to adjust training loads.^[50]

Evaluation Metrics

Traditional Statistics

Traditional statistics for evaluating starting pitchers focus on basic outcomes from games, providing straightforward measures of effectiveness derived from box scores and official scoring rules. These metrics emphasize runs allowed, team results tied to the pitcher's performance, and control over baserunners and strikeouts, forming the foundation of pitcher assessment since the early days of Major League Baseball (MLB).^[51] The Earned Run Average (ERA) is a primary indicator of a starting pitcher's ability to prevent runs, calculated as the number of earned runs allowed multiplied by 9, then divided by innings pitched. Earned runs exclude those scored due to defensive errors, isolating the pitcher's responsibility. For example, a pitcher allowing 20 earned runs over 100 innings has an ERA of 1.80, signifying strong performance relative to the league average, which has hovered around 4.00 in recent decades. Wins and losses track a starting pitcher's direct contribution to team victories and defeats, assigned based on official scoring rules. A starting pitcher earns a win if they pitch at least five innings and their team takes the lead for good while they are the pitcher of record, meaning they were pitching when the team first gained the eventual winning margin. Losses are credited similarly if the team trails when the pitcher leaves and does not regain the lead, though starters can receive a loss without the five-inning minimum if replaced early with their team behind. These decisions reflect team support as much as individual skill, with top starters typically aiming for 15-20 wins in a 162-game season.^[52]^[53]^[54] The Walks plus Hits per Inning Pitched (WHIP) measures a pitcher's control by averaging total baserunners (walks and hits) allowed per inning, computed as (walks + hits) divided by innings pitched. A WHIP below 1.20 is considered elite for starting pitchers, indicating minimal traffic on the bases and lower scoring opportunities for opponents. Complete games occur when a starting pitcher delivers all nine (or more) innings for their team without relief, a feat that highlights endurance and dominance. Shutouts are a subset, defined as complete games where no runs are allowed. Historically, complete games were routine in the early 20th century, with pitchers like Walter Johnson logging over 400 in his career, but their frequency has declined sharply due to modern workload management and bullpen specialization. In the 2020s, complete games represent fewer than 1% of all starts, with MLB recording just 26 in 2024 across over 9,700 starting appearances—the lowest total in history. Shutouts, similarly rare today, underscore exceptional outings, as seen in Nolan Ryan's MLB-record 61.^[55] Strikeouts per nine innings (K/9) quantifies a pitcher's ability to generate swing-and-misses, calculated as (strikeouts × 9) divided by innings pitched, with elite starters often exceeding 9.0 K/9. Conversely, walks per nine innings (BB/9) assesses command, using the same formula for walks, where rates below 3.0 signal strong control and fewer free bases. These ratios provide normalized views of dominance and discipline, essential for starting pitchers who face lineups multiple times per game.

Advanced Analytics

Advanced analytics in evaluating starting pitchers emphasize metrics that isolate a pitcher's individual contributions from external factors like defense or luck, providing deeper insights into skill and future performance. These tools, powered by data from systems like Statcast, focus on outcomes independent of batted-ball results and predictive modeling to forecast value.^[56] Fielding Independent Pitching (FIP) is a key metric that estimates a pitcher's ERA based solely on events they control: home runs, walks, hit-by-pitches, and strikeouts. The formula is:

\text{FIP} = \frac{13 \times \text{HR} + 3 \times (\text{BB} + \text{HBP}) - 2 \times \text{K}}{\text{IP}} + \text{constant}

where the constant scales FIP to league-average ERA, typically around 3.10 to 3.20. Developed by Tom Tango and inspired by Voros McCracken's Defense Independent Pitching Statistics (DIPS) theory, FIP credits pitchers for preventing home runs (weighted heavily at 13) while penalizing free passes (at 3) and rewarding strikeouts (at -2), ignoring batted balls in play as largely unpredictable.^[57]^[58]^[56] Expected ERA (xERA), derived from Statcast data and introduced in 2020, predicts a pitcher's ERA by modeling run expectancy from batted-ball quality rather than actual outcomes. It translates Expected Weighted On-Base Average (xwOBA) directly to the ERA scale, using exit velocity, launch angle, and sprint speed to estimate what results should occur based on contact quality. This helps identify pitchers whose ERAs overperform or underperform due to defensive support or sequencing luck.^[59]^[60] Wins Above Replacement (WAR) measures a starting pitcher's total value to their team compared to a replacement-level player, typically a minor leaguer or bench option. For pitchers, WAR combines innings pitched, run prevention (often via FIP or RA9—Runs Allowed per 9 innings), and leverage adjustments, with formulas varying by provider: FanGraphs uses FIP-based WAR, while Baseball-Reference employs RA9. Elite starters contribute 4-6+ WAR per season, influencing roster decisions, trades, and contracts by quantifying overall impact beyond single metrics.^[61]^[62] At the pitch level, Statcast enables analysis of spin rate and movement profiles, quantifying a pitch's raw effectiveness. Spin rate, measured in revolutions per minute (RPM), influences break and deception; for curveballs, elite examples exceed 2400 RPM, enhancing vertical drop and sweep to evade hitters. Movement profiles track horizontal and vertical deviation, release point, and extension, revealing how pitches behave in flight. Stuff+ , a FanGraphs metric, standardizes these physical traits (velocity, spin, movement, release) across pitch types into a run-value scale where 100 is average, allowing comparison of arsenals independent of location or sequencing.^[63]^[64]^[65] Projection systems like PECOTA and Steamer forecast starting pitcher performance by blending historical data, aging curves, and adjustments for park factors, opponent strength, and role. PECOTA, developed by Baseball Prospectus, compares a player's past seasons to similar historical archetypes, generating probabilistic outcomes for metrics like innings pitched and ERA. Steamer, hosted by FanGraphs, uses a regression-based approach incorporating recent performance and minor-league translations, often pro-rating for rest-of-season scenarios while normalizing for ballpark effects. These tools aid in valuing starters for fantasy, trades, and contracts by predicting WAR contributions.^[66]^[67]

References

[1]
Games Started (GS) | Glossary - MLB.com
Games Started (GS). Definition. A pitcher is credited with a game started if he is the first pitcher to throw a pitch for his team in a given game.
[2]
Starting Pitcher - Baseball-Reference.com
A starting pitcher is a pitcher who starts the game and usually pitches 6 or more innings, after which relief pitchers close out the game.
[3]
Starting Pitching Is Important, Too - FanGraphs Baseball
Oct 21, 2016 · When starters have pitched well, their teams have generally won. Conversely, when starters have pitched poorly, their teams have lost.
[4]
Baseball Prospectus Basics: A Brief History of Pitcher Usage
Mar 2, 2004 · The notion of using your starting pitcher–often your best starting pitcher–in relief as the need arose, blossomed in the 1910s and stayed popular for over 30 ...
[5]
https://www.drivelinebaseball.com/2025/03/return-of-the-starting-pitcher/
[6]
Starting Pitcher | Glossary - MLB.com
Teams in today's game typically rotate between five starting pitchers, meaning starters usually have four to five days off between trips to the mound.
[7]
https://www.platecrate.com/blogs/baseball-101/how-many-innings-do-pitchers-pitch-understanding-the-modern-game
[8]
Relief Pitcher | Glossary - MLB.com
Relief pitchers enter games after the starting pitcher has been removed, usually as a result of poor performance, high pitch count or injury.
[9]
How starting pitchers transition to the bullpen - MLB.com
Sep 2, 2023 · When you're a starting pitcher, your job the first time through the order is to dance around a lineup, never giving away too much in one at-bat ...<|control11|><|separator|>
[10]
https://www.baseball-reference.com/bullpen/Starting_pitcher
[11]
The Role of Two-Pitch Sequences in Pitching Success
May 28, 2023 · The nature of this matchup between the pitcher-catcher duo and a batter is sequential. The pitcher acts and is met with a reaction by the batter ...
[12]
When to walk (Part 1) - The Hardball Times - FanGraphs
May 16, 2008 · Generally, an intentional walk is a poor strategy, other than perhaps with two outs, runners on second and third, and an unprotected elite hitter at the plate.
[13]
Candy Cummings – Society for American Baseball Research
Jan 4, 2012 · In 1867, after four years of ... For the next several decades, Cummings passionately defended his status as the inventor of the curveball.
[14]
An Analysis of Pre-Modern Pitchers
Feb 18, 2011 · Pitching staffs also evolved. Teams had a single dominant pitcher in the 1870s. This produced seasons with the lead pitcher starting 60+ games, ...
[15]
October 7, 1867: Candy Cummings debuts the curve
Oct 23, 2014 · October 7, 1867: Candy Cummings debuts the curve ... One of the oldest, most venerable weapons in the pitcher's arsenal is the curveball. Various ...Missing: invention | Show results with:invention
[16]
William Hulbert: Father of Professional Sports Leagues
The ultimate creation of the National League of Professional Base Ball Clubs in early 1876 was a major surprise to most of the baseball world.
[17]
Old Hoss Radbourn - Society for American Baseball Research
Jan 4, 2012 · For the first time, the National League allowed pitchers to raise their arm above their shoulder, effectively legalizing the overhand delivery.<|control11|><|separator|>
[18]
The History of Relief Pitching Part One: 1871-1945
Jul 16, 2017 · In the first 75 years of Major League Baseball, the vast majority of relief appearances were made by starting pitchers, including by notable ...
[19]
Pitching: Evolution and Revolution | by John Thorn | Our Game
Aug 6, 2014 · In the first survivng rules of baseball, drafted by William R. Wheaton and William H. Tucker for the Knickerbocker Base Ball Club in 1845, ...
[20]
The History of Relief Pitching Part Two: 1946-1968
Oct 23, 2017 · 1946-1968: The Emergence of the Bullpen Specialist · % G as CG = the percentage of all games started that ended in a complete game · % G as RP = ...<|control11|><|separator|>
[21]
When Did the Designated Hitter Rule Start in Baseball - Refr Sports
Apr 7, 2024 · It has increased offensive production, created strategic differences between leagues, and allowed for greater specialization of player roles.
[22]
History of the Designated Hitter Rule - Baseball Egg
Feb 21, 2024 · Traditionalists argue that the designated hitter disrupts the purity of the game and alters the strategic nuances of National League baseball, ...
[23]
Steroids' benefits for pitchers questionable - NBC News
Apr 30, 2006 · While drug experts largely agree that steroids can enhance any hitter's power and likely fueled the unprecedented home run surge in the 1990s, ...
[24]
An Old-School Pitching Coach Says I Told You So - The Atlantic
May 10, 2025 · Compared with today, pitchers were at a far greater disadvantage in the '90s and 2000s—baseball's Frankenstein Era, when steroids were rampant ...
[25]
A Deeper Dive Into Pitcher Usage Trends - FanGraphs Baseball
May 7, 2024 · For the last two years in aggregate, starters are down an average of 9.2 pitches and .67 innings per start from the numbers they averaged from ...
[26]
Can MLB save the starting pitcher? The search for solutions to ...
Jun 5, 2024 · Last year, the length of the average major-league start plunged to an all-time low: 15 outs (or five innings) per start. Not even starting ...
[27]
Starting Pitching's Downward Spiral Shows No Sign of Slowing
May 22, 2023 · From 2014 to this year, the percentage of quality starts (at least six innings with no more than three earned runs) has dropped from 54% to 35%.
[28]
MLB 2023 rule changes: pitch timer, larger bases, shifts
Feb 1, 2023 · Between pitches, there will be a 15-second timer with the bases empty and a 20-second timer with runners on base. At last check, the pitch timer ...
[29]
(PDF) How Did the Pitch Clock Impact the 2023 Major League ...
Aug 28, 2025 · Games were about 13 percent shorter, attendance increased for most clubs, and overall team pitching suffered (team ERAs and WHIPs, on average, ...Missing: outings | Show results with:outings
[30]
Identifying Pitch Types: A Fan's Guide - MLB.com
Jun 1, 2019 · Let's start with a slider. The slider moves sideways, in the same direction as a cutter -- right to left for a right-handed pitcher, left to ...
[31]
Building a Pitch Arsenal for High School Athletes | Rapsodo® Baseball
Nov 1, 2023 · A deceptive off-speed pitch can be a game-changer since it looks like a fastball, further deceiving the batters. When it comes to off-speed ...
[32]
Pitch Tunneling: Is It Real? And How Do Pitchers Actually Pitch?
Jun 16, 2017 · Though a pitcher's ability to use tunneled sequences may increase deception, pitchers select sequences based on expected outcomes. If the ...Missing: building | Show results with:building
[33]
A Closer Look at Pitch Tunneling - Pitcher List
Mar 31, 2021 · My goal with TotalTunnel as a predictor of Expected Run Value was to model how pitches play off of each other through visual deception. Not only ...
[34]
Which Pitch Should Be Thrown Next? - the FanGraphs Community
Aug 20, 2021 · Conclusions · If a pitcher has the platoon advantage, a fastball or slider is the most effective pitch to throw to start the plate appearance.
[35]
A Decision Tree Approach to Pitch Prediction | The Hardball Times
Mar 17, 2014 · A quick example: Let's say the first branch of Greinke's tree is the handedness of the hitter he's facing. If the hitter is a righty, Greinke's ...<|control11|><|separator|>
[36]
https://baseballmode.com/blogs/blog/how-do-pitching-rotations-work
[37]
Northwestern study looks for jet lag's effects by analyzing 20 ... - ESPN
Jan 23, 2017 · After traveling eastward, jet-lagged home teams hit fewer doubles and triples, stole fewer bases and grounded into more double plays than when ...
[38]
How weather guided Major League Baseball schedule-makers ...
Aug 14, 2019 · “We took weather into consideration and incorporated various factors into the 2020 schedule for the first two series of the year,” MLB Vice ...<|separator|>
[39]
Snyder's Soapbox: An ode to the lost days of the complete game ...
Apr 23, 2024 · In 2004, starters averaged 5.9 innings per start, so basically just six. · In 1984, the average was about 6 1/3 innings. · In 1954, it was 6 2/3.Missing: analytics | Show results with:analytics
[40]
MLB sabermetrics, analytics redefining baseball in 2025
May 9, 2025 · With the help of modern technology, sports analytics proves that pitchers are, on average, less effective the longer they pitch.Missing: goals | Show results with:goals
[41]
https://www.drivelinebaseball.com/2025/09/in-search-of-a-smarter-pitch-count/
[42]
Decline of starting pitching bad for baseball - Robert Whiting's Japan
May 13, 2024 · The numbers were 17.4 and 93.1 as late as 2015, and 17.8 and 98.6 in 2000. Innings per start fell from 6.03 in 2011 to 5.22 this year. As ...Missing: 2020s | Show results with:2020s
[43]
What doctors wish patients knew about Tommy John surgery
Jul 12, 2024 · The share of active major-league pitchers who had undergone Tommy John surgery hit 35.3% in 2023, a 29% rise since 2016. Why vaccines matter to ...Tommy John surgery changed... · Prevalence among kids is risingMissing: 2020s | Show results with:2020s
[44]
Shoulder Injuries in Professional Baseball Batters: Analysis of ... - NIH
May 21, 2022 · Rotator cuff strain/tears was the most common diagnosis (n = 790; 23.1%), and SLAP tears had the highest season-ending rate (35.3%) and need for ...
[45]
Baseball Pitching Biomechanics in Relation to Injury Risk and ... - NIH
As with most other athletic movements, the biomechanics of baseball pitching is studied to improve performance and prevent and/or rehabilitate injury. As ...
[46]
Position Statement for Tommy John Injuries in Baseball Pitchers
“Too much pitching is a big reason for all of the Tommy John injuries these days.” Exactly. When an orthopaedist performs surgery on a torn ulnar collateral ...
[47]
Pitching - Driveline Baseball
### Summary of Driveline Baseball's Offseason Conditioning Programs for Pitchers
[48]
Tommy John Surgery | Glossary - MLB.com
Pitchers who have undergone Tommy John surgery are usually given a recovery timetable of 12 to 18 months. The recovery time is much less certain for those ...
[49]
Pitch Smart | Guidelines - MLB.com
Pitch Smart guidelines use age-based pitch count limits and required rest recommendations to limit fatigue. Organizations should set rules for players to ...Ages 9-12 · Ages 13-14 · Ages 15-18 · Ages 19-22
[50]
A Review of Workload-Monitoring Considerations for Baseball Pitchers
Sep 19, 2020 · Current techniques for monitoring baseball pitchers' workloads have relied exclusively on in-game pitch counts. The volume and intensity of ...
[51]
Standard Stats | Glossary - MLB.com
For Pitchers: Wins; ERA; WHIP; Strikeouts; Saves. In this section, you will find explanations of baseball's standard stats. Often seen on the ...
[52]
Win (W) | Glossary - MLB.com
First, a starting pitcher must pitch at least five innings (in a traditional game of nine innings or longer) to qualify for the win. If he does not, the ...
[53]
Loss (L) | Glossary - MLB.com
A starting pitcher does not necessarily receive a loss every time his team loses -- even if he exits the game with his team trailing. In such instances, if ...
[54]
Win - BR Bullpen - Baseball-Reference.com
Jan 31, 2024 · A starting pitcher must pitch for at least 5 innings to receive credit for a win, unless the game goes only 5 innings (in which case he must ...
[55]
MLB pitchers threw fewer complete games but dominated batters ...
Oct 1, 2024 · The complete game total was down from 35 last year and 36 in 2022. There were 50 in 2021, 104 in 2015, 209 in 2003 and 622 in 1988. Related ...
[56]
FIP - Sabermetrics Library - FanGraphs
Feb 15, 2010 · Fielding Independent Pitching (FIP) measures what a player's ERA ... Here is the formula for FIP: FIP = ((13*HR)+(3*(BB+HBP))-(2*K))/IP ...Missing: origin | Show results with:origin
[57]
Fielding Independent Pitching (FIP) | Glossary - MLB.com
Where the "FIP constant" puts FIP onto the same scale as the entire league's ERA: ((HR x 13) + (3 x (BB + HBP)) - (2 x K)) / IP + FIP constant. More from ...Missing: origin | Show results with:origin
[58]
FIP, In Context | The Hardball Times - FanGraphs
Mar 11, 2015 · Voros McCracken is credited with starting the movement, but Tom Tango is responsible for the most widely-used DIPS-type equation: Fielding ...Missing: origin | Show results with:origin
[59]
Statcast primer: Baseball will never be the same | MLB.com
Apr 24, 2015 · Statcast, a state-of-the-art tracking technology, is capable of gathering and displaying previously immeasurable aspects of the game.
[60]
Expected ERA (xERA) | Glossary - MLB.com
Expected ERA, or xERA, is a simple 1:1 translation of Expected Weighted On-Base Average (xwOBA), converted to the ERA scale.
[61]
Statcast Metrics Context | baseballsavant.com - MLB.com
How far off the mound, in feet, a pitcher releases the pitch. Expected Earned Run Avg (xERA). xERA is a simple 1:1 translation of xwOBA, converted to the ERA ...
[62]
https://library.fangraphs.com/misc/war/
[63]
Stuff+, Location+, and Pitching+ Primer - Sabermetrics Library
Mar 10, 2023 · Stuff+ looks at pitch physical characteristics, Location+ at placement, and Pitching+ uses both to judge a pitcher's process.
[64]
PECOTA Projections | Baseball Prospectus
PECOTA is a system that takes a player's past performance and tries to project the most likely outcome for the following season.
[65]
2026 Projections - Steamer | FanGraphs Baseball
They represent a player's current seasons stats pro-rated for the remaining games in the season if they were to play in every single ...Steamer (RoS) · Steamer (Update) · ZiPS · Steamer600