Category

Term	Abbreviation	Category	Description	Usage & Notes
Arizona Diamondbacks	ARI	Teams & Nicknames	National League West franchise (est. 1998) playing home games at Chase Field in Phoenix, Arizona.	Common nicknames: D-backs and Snakes. Scoreboards list them as ARI.
Colorado Rockies	COL	Teams & Nicknames	National League West franchise (est. 1993) playing home games at Coors Field in Denver, Colorado.	Common nicknames: Rox and Rockies. Scoreboards list them as COL.
Los Angeles Dodgers	LAD	Teams & Nicknames	National League West franchise (est. 1883) playing home games at Dodger Stadium in Los Angeles, California.	Common nicknames: Dodgers and Boys in Blue. Scoreboards list them as LAD.
San Diego Padres	SD	Teams & Nicknames	National League West franchise (est. 1969) playing home games at Petco Park in San Diego, California.	Common nicknames: Pads and Friars. Scoreboards list them as SD.
San Francisco Giants	SF	Teams & Nicknames	National League West franchise (est. 1883) playing home games at Oracle Park in San Francisco, California.	Common nicknames: Giants and Orange and Black. Scoreboards list them as SF.
Atlanta Braves	ATL	Teams & Nicknames	National League East franchise (est. 1876) playing home games at Truist Park in Cumberland, Georgia.	Common nicknames: Braves and Bravos. Scoreboards list them as ATL.
Miami Marlins	MIA	Teams & Nicknames	National League East franchise (est. 1993) playing home games at loanDepot park in Miami, Florida.	Common nicknames: Marlins and Fish. Scoreboards list them as MIA.
New York Mets	NYM	Teams & Nicknames	National League East franchise (est. 1962) playing home games at Citi Field in Queens, New York.	Common nicknames: Mets and Amazin's. Scoreboards list them as NYM.
Philadelphia Phillies	PHI	Teams & Nicknames	National League East franchise (est. 1883) playing home games at Citizens Bank Park in Philadelphia, Pennsylvania.	Common nicknames: Phillies and Fightin' Phils. Scoreboards list them as PHI.
Washington Nationals	WSH	Teams & Nicknames	National League East franchise (est. 1969) playing home games at Nationals Park in Washington, DC.	Common nicknames: Nats and Nationals. Scoreboards list them as WSH.
Chicago Cubs	CHC	Teams & Nicknames	National League Central franchise (est. 1876) playing home games at Wrigley Field in Chicago, Illinois.	Common nicknames: Cubbies and North Siders. Scoreboards list them as CHC.
Cincinnati Reds	CIN	Teams & Nicknames	National League Central franchise (est. 1882) playing home games at Great American Ball Park in Cincinnati, Ohio.	Common nicknames: Reds and Big Red Machine. Scoreboards list them as CIN.
Milwaukee Brewers	MIL	Teams & Nicknames	National League Central franchise (est. 1969) playing home games at American Family Field in Milwaukee, Wisconsin.	Common nicknames: Crew and Brew Crew. Scoreboards list them as MIL.
Pittsburgh Pirates	PIT	Teams & Nicknames	National League Central franchise (est. 1882) playing home games at PNC Park in Pittsburgh, Pennsylvania.	Common nicknames: Pirates and Bucs. Scoreboards list them as PIT.
St. Louis Cardinals	STL	Teams & Nicknames	National League Central franchise (est. 1882) playing home games at Busch Stadium in St. Louis, Missouri.	Common nicknames: Cards and Redbirds. Scoreboards list them as STL.
Baltimore Orioles	BAL	Teams & Nicknames	American League East franchise (est. 1954) playing home games at Oriole Park at Camden Yards in Baltimore, Maryland.	Common nicknames: O's and Birdland. Scoreboards list them as BAL.
Boston Red Sox	BOS	Teams & Nicknames	American League East franchise (est. 1901) playing home games at Fenway Park in Boston, Massachusetts.	Common nicknames: Red Sox and BoSox. Scoreboards list them as BOS.
New York Yankees	NYY	Teams & Nicknames	American League East franchise (est. 1901) playing home games at Yankee Stadium in Bronx, New York.	Common nicknames: Yankees and Bronx Bombers. Scoreboards list them as NYY.
Tampa Bay Rays	TB	Teams & Nicknames	American League East franchise (est. 1998) playing home games at Tropicana Field in St. Petersburg, Florida.	Common nicknames: Rays and Devil Rays. Scoreboards list them as TB.
Toronto Blue Jays	TOR	Teams & Nicknames	American League East franchise (est. 1977) playing home games at Rogers Centre in Toronto, Ontario.	Common nicknames: Blue Jays and Jays. Scoreboards list them as TOR.
Chicago White Sox	CWS	Teams & Nicknames	American League Central franchise (est. 1901) playing home games at Guaranteed Rate Field in Chicago, Illinois.	Common nicknames: White Sox and South Siders. Scoreboards list them as CWS.
Cleveland Guardians	CLE	Teams & Nicknames	American League Central franchise (est. 1901) playing home games at Progressive Field in Cleveland, Ohio.	Common nicknames: Guardians and Guards. Scoreboards list them as CLE.
Detroit Tigers	DET	Teams & Nicknames	American League Central franchise (est. 1901) playing home games at Comerica Park in Detroit, Michigan.	Common nicknames: Tigers and Motor City Kitties. Scoreboards list them as DET.
Kansas City Royals	KC	Teams & Nicknames	American League Central franchise (est. 1969) playing home games at Kauffman Stadium in Kansas City, Missouri.	Common nicknames: Royals and Boys in Blue. Scoreboards list them as KC.
Minnesota Twins	MIN	Teams & Nicknames	American League Central franchise (est. 1901) playing home games at Target Field in Minneapolis, Minnesota.	Common nicknames: Twins and Twinkies. Scoreboards list them as MIN.
Houston Astros	HOU	Teams & Nicknames	American League West franchise (est. 1962) playing home games at Minute Maid Park in Houston, Texas.	Common nicknames: Astros and Stros. Scoreboards list them as HOU.
Los Angeles Angels	LAA	Teams & Nicknames	American League West franchise (est. 1961) playing home games at Angel Stadium in Anaheim, California.	Common nicknames: Angels and Halos. Scoreboards list them as LAA.
Oakland Athletics	OAK	Teams & Nicknames	American League West franchise (est. 1901) playing home games at Oakland Coliseum in Oakland, California.	Common nicknames: A's and Green and Gold. Scoreboards list them as OAK.
Seattle Mariners	SEA	Teams & Nicknames	American League West franchise (est. 1977) playing home games at T-Mobile Park in Seattle, Washington.	Common nicknames: Mariners and M's. Scoreboards list them as SEA.
Texas Rangers	TEX	Teams & Nicknames	American League West franchise (est. 1961) playing home games at Globe Life Field in Arlington, Texas.	Common nicknames: Rangers and Lone Star Nine. Scoreboards list them as TEX.
Launch Angle	—	Hitting Concepts	Vertical angle at which the ball leaves the bat relative to the ground.	Optimizing launch angle helps produce line drives and home runs.
Exit Velocity	EV	Hitting Concepts	Speed of the baseball as it leaves the bat, typically measured in miles per hour.	Higher exit velocity correlates with stronger contact and better offensive outcomes.
Barrel	—	Hitting Concepts	Statcast classification for batted balls with optimal exit velocity and launch angle combinations.	Barrel rate is a shorthand for how often a hitter produces elite contact.
Hard-Hit Rate	—	Hitting Concepts	Percentage of batted balls struck at 95 miles per hour or harder.	Highlights hitters who consistently drive the ball with authority.
Bat Speed	—	Hitting Concepts	The rate at which the bat travels through the hitting zone, often tracked by motion sensors.	Faster bat speed allows hitters to wait longer and still drive the ball with power.
Sweet Spot Percentage	—	Hitting Concepts	Share of batted balls hit with a launch angle between 8 and 32 degrees, the most productive window.	Complements exit velocity by identifying hitters who live in the best contact window.
Line Drive	—	Hitting Concepts	Batted ball hit on a relatively low, straight trajectory with minimal arc.	Produces the highest batting average of any batted-ball type.
Fly Ball	—	Hitting Concepts	Batted ball hit on an upward trajectory that stays in the air for an extended time.	Fly-ball hitters often trade batting average for slugging potential.
Ground Ball	—	Hitting Concepts	Batted ball that strikes the ground quickly and stays on the infield surface.	Ground-ball-heavy hitters rely on speed and finding holes rather than power.
Pull Hitter	—	Hitting Concepts	Batter who most often hits the ball to the side of the field corresponding to his pull hand.	Pull hitters face defensive shifts but can generate power by turning on pitches.
Opposite-Field Hitter	—	Hitting Concepts	Batter who frequently drives the ball to the field opposite his pull side.	Opposite-field approach counters shifts and indicates strong plate coverage.
Spray Chart	—	Hitting Concepts	Visual plot showing where a hitter's batted balls land across the field.	Coaches study spray charts to design defensive positioning and identify tendencies.
Plate Discipline	—	Hitting Concepts	A hitter's ability to distinguish strikes from balls and choose which pitches to swing at.	Strong plate discipline leads to more walks, fewer chases, and better counts.
Chase Rate	—	Hitting Concepts	Percentage of swings at pitches located outside the strike zone.	Lower chase rates signify patience and sharpen on-base skills.
Contact Rate	—	Hitting Concepts	Percentage of swings that result in the batter making contact with the ball.	High contact rates reduce strikeouts and sustain table-setting hitters.
Situational Hitting	—	Hitting Concepts	Approach focused on advancing runners or producing the needed result rather than personal stats.	Includes executing sacrifice flies, hitting behind the runner, or shortening the swing with two strikes.
Four-Seam Fastball	—	Pitching Approaches	Straightest and firmest fastball gripped across the seams to create backspin and ride.	Primary pitch for many starters and relievers to establish counts and elevate for strikeouts.
Two-Seam Fastball	—	Pitching Approaches	Fastball gripped along the seams that features arm-side movement and sink.	Generates ground balls and weak contact when located down in the zone.
Sinker	—	Pitching Approaches	Hard fastball variant with heavy downward movement designed to induce grounders.	Effective when started at the knees and allowed to dive below barrels.
Cutter	—	Pitching Approaches	Fastball with late glove-side movement that breaks bats and misses barrels.	Mariano Rivera popularized the pitch as a late-inning weapon against both handednesses.
Slider	—	Pitching Approaches	Breaking ball thrown with tight spin that sweeps laterally with some depth.	Used as a chase pitch when buried or as a backdoor strike when started off the plate.
Curveball	—	Pitching Approaches	Arcing breaking ball with significant top-spin that causes sharp downward break.	Effective when tunneled off fastballs to disrupt timing and eye level.
Changeup	—	Pitching Approaches	Off-speed pitch thrown with fastball arm action to disrupt timing with reduced velocity.	Most effective fading away from opposite-handed hitters to induce weak contact.
Splitter	—	Pitching Approaches	Pitch gripped between the index and middle fingers that drops sharply late.	Works as a strikeout pitch when tunneled off the fastball due to late tumble.
Knuckleball	—	Pitching Approaches	Slow pitch thrown with minimal spin that dances unpredictably through the air.	Requires a specialized catcher and can neutralize power lineups when commanded.
Spin Rate	RPM	Pitching Approaches	Revolutions per minute generated on a pitch, influencing movement and perceived rise or drop.	Higher spin boosts hop on fastballs and sharpens breaking pitches when paired with proper axis.
Pitch Tunneling	—	Pitching Approaches	Designing pitch sequences so multiple offerings share the same early trajectory before diverging late.	Enhances deception, making fastballs and breaking balls harder to distinguish for hitters.
Pitch Count	—	Pitching Approaches	Total number of pitches thrown by a pitcher in an outing or over a season.	Teams monitor pitch counts to manage fatigue, injury risk, and bullpen planning.
Walks plus Hits per Inning Pitched	WHIP	Pitching Approaches	Measures how many baserunners a pitcher allows per inning via walks and hits.	Lower WHIP indicates better command and fewer baserunners against the pitcher.
Opener Strategy	—	Pitching Approaches	Deploying a reliever to start the game for one or two innings before handing the ball to a bulk pitcher.	Helps teams manage matchups at the top of the order and protect young starters.
Infield Shift	—	Defensive Alignments	Adjusting infielders toward one side of the field based on a hitter's tendencies.	Teams deploy a shift to cut off hard grounders; new rules now limit extreme positioning.
Double-Play Depth	—	Defensive Alignments	Infielders position themselves slightly closer to second base to turn double plays more quickly.	Common when there's a runner on first with fewer than two outs and a ground-ball pitcher on the mound.
Infield In	—	Defensive Alignments	Moving all infielders closer to home plate to cut down a runner trying to score.	Used with a runner on third and fewer than two outs in late-inning, one-run situations.
Corners In	—	Defensive Alignments	First and third basemen charge closer to home plate to defend against a bunt or squeeze play.	Triggered when the batter is a good bunter or the situation suggests a squeeze attempt.
No-Doubles Defense	—	Defensive Alignments	Outfielders play deeper and corner infielders guard the lines to prevent extra-base hits.	Common in late innings when protecting a narrow lead and the tying run is on base.
Wheel Play	—	Defensive Alignments	Third baseman charges the bunt while shortstop covers third and first baseman crashes with second covering first.	Used to defend against squeeze bunts with a runner on third and one out or fewer.
Cutoff Man	—	Defensive Alignments	Infielder who positions himself between the outfielder and the target base to redirect a throw.	Keeps throws on line and allows defenses to adjust the target once the play develops.
Relay Throw	—	Defensive Alignments	A two-step throw from the outfield to an infielder and onward to a base to retire a runner.	Critical on deep hits when the outfielder cannot reach the target base with one throw.
Tag Play	—	Defensive Alignments	Defensive action of touching a runner with the ball or glove while holding the ball to record an out.	Essential on steals, rundowns, and plays at the plate where force plays do not apply.
Rundown	—	Defensive Alignments	Fielders trap a runner between bases, exchanging throws until he is tagged out or escapes.	Requires short, controlled throws and decisive tags to avoid errors that allow advancement.
Outfield Assist	—	Defensive Alignments	When an outfielder throws to a base or home plate to retire an advancing runner.	Highlights strong outfield arms and accurate throws that change innings.
Pitch Framing	—	Defensive Alignments	Catcher's subtle glove movements that present borderline pitches as strikes to the umpire.	Analytics now quantify framing value, influencing catcher evaluations and playing time.
Small Ball	—	Game Strategy	Offensive approach focused on bunting, stealing, and advancing runners one base at a time.	Used when teams value a single run, often in tight games or pitcher duels.
Hit and Run	—	Game Strategy	The runner breaks for the next base as the batter swings to put the ball in play behind them.	Designed to stay out of double plays and open gaps by moving infielders.
Squeeze Play	—	Game Strategy	Runner on third breaks for home as the batter bunts, aiming to score before the defense can field the ball.	High-risk move often reserved for late innings when a single run is vital.
Safety Squeeze	—	Game Strategy	Variation of the squeeze where the runner waits to break from third until the batter deadens the bunt.	Employed when managers want insurance the ball is down before sending the runner.
Sacrifice Bunt	—	Game Strategy	Batter bunts the ball intending to be thrown out while advancing a baserunner into scoring position.	Most common with a light-hitting pitcher or late in tie games to play for a single run.
Double Switch	—	Game Strategy	National League tactic where a manager substitutes a pitcher and position player simultaneously to reorder the batting lineup.	Keeps a reliever out of the imminent batter's box and maximizes matchup flexibility late in games.
Bullpen Day	—	Game Strategy	Game planned around multiple relievers covering all innings instead of a traditional starter.	Used to manage workloads during congested schedules or when a rotation spot lacks a healthy starter.
Platoon Advantage	—	Game Strategy	Strategy of aligning hitters and pitchers to exploit favorable left-right matchups.	Managers rotate platoon partners to keep hitters fresh and press the advantage late in games.
Intentional Walk Strategy	—	Game Strategy	Choosing to award first base to a hitter to create a force play, set up a double play, or face a weaker matchup.	Managers weigh game state, base occupancy, and the on-deck hitter before issuing the four-finger signal.
Batting Average	AVG	Advanced Stats	Ratio of a hitter's hits to official at-bats.	Long-time standard for measuring contact ability, though it ignores walks and power.
On-Base Percentage	OBP	Advanced Stats	Measures how often a batter reaches base via hit, walk, or hit-by-pitch per plate appearance.	Rewards players who work counts and reach base beyond pure hitting average.
Slugging Percentage	SLG	Advanced Stats	Total bases divided by at-bats, weighting extra-base hits more heavily than singles.	Combined with OBP to gauge overall offensive production.
On-base Plus Slugging	OPS	Advanced Stats	Sum of on-base percentage and slugging percentage as a quick measure of overall offense.	Useful shorthand for comparing hitters across eras, though it values all components equally.
OPS Plus	OPS+	Advanced Stats	Normalizes OPS for league and park factors, centering 100 as league average.	Values above 100 indicate above-average production while below 100 signals below-average hitters.
Weighted On-base Average	wOBA	Advanced Stats	Assigns run-value weights to different outcomes to better capture offensive contribution per plate appearance.	Core component of advanced metrics like wRC+ and more predictive than OPS alone.
Weighted Runs Created Plus	wRC+	Advanced Stats	Adjusts weighted runs created for league and park, scaling 100 as average offensive output.	Preferred stat for comparing hitters across environments because it weights events and context.
Wins Above Replacement	WAR	Advanced Stats	Comprehensive metric estimating how many wins a player adds compared to a replacement-level player.	Used to compare overall value across positions; different providers publish slightly different WAR formulas.
Batting Average on Balls in Play	BABIP	Advanced Stats	Batting average calculated only on balls hit into the field of play, excluding home runs and strikeouts.	Highlights luck and defense behind outcomes; extreme BABIP swings often regress toward career norms.
Earned Run Average	ERA	Advanced Stats	Average number of earned runs a pitcher allows per nine innings pitched.	Traditional pitching barometer, though influenced by defense and scoring decisions.
Fielding Independent Pitching	FIP	Advanced Stats	Estimates pitcher performance based on strikeouts, walks, hit batters, and home runs, removing defensive impact.	Better predictor of future ERA than past ERA because it focuses on outcomes pitchers control.
Strikeout Rate	K%	Advanced Stats	Percentage of batters faced that a pitcher strikes out, or of plate appearances a hitter ends in strikeouts.	High strikeout rates limit balls in play and are prized for both pitchers and hitters' evaluation.
Walk Rate	BB%	Advanced Stats	Percentage of plate appearances that result in a walk, for either pitchers or hitters.	Low walk rates signal pitcher control, while high rates reflect hitter patience.
Strikeout-to-Walk Ratio	K/BB	Advanced Stats	Ratio comparing strikeouts to walks, illustrating command and dominance.	Higher ratios mean pitchers avoid free passes while missing bats at elite rates.
Quality Start	QS	Advanced Stats	Start in which a pitcher works at least six innings and allows three earned runs or fewer.	Serves as a baseline for dependable outings, though it does not account for bullpen leverage or dominance.
Left on Base Percentage	LOB%	Advanced Stats	Share of baserunners a pitcher strands on base without allowing them to score.	Extreme strand rates tend to regress and help evaluate whether ERA aligns with peripherals.
Save	SV	Advanced Stats	Credited to a relief pitcher who finishes a game for the winning team under specific leverage conditions.	Traditional measure for closers, though modern analysis also weighs leverage index and strikeout skills.
Infield Fly Rule	—	Rules & Regulations	Declares the batter out on a fair infield pop-up with runners on base and fewer than two outs to prevent easy double plays.	Umpires call "Infield Fly, batter's out" while the ball is in the air; runners may advance at their own risk.
Pitch Clock	—	Rules & Regulations	Limits the time pitchers and batters can take between pitches to improve pace of play.	Violations add a ball to the count for pitchers or a strike for hitters if they are not ready in time.
Balk	—	Rules & Regulations	Illegal pitching movement with runners on base that deceives the runner, resulting in all runners advancing one base.	Common balk calls include failing to come set, flinching during the stretch, or faking a throw to first without stepping off.
Designated Hitter Rule	DH	Rules & Regulations	Allows teams to bat a designated hitter in place of the pitcher without forfeiting the pitcher's defensive role.	Adopted universally in 2022, the DH boosts offense and extends careers for limited-fielding sluggers.
Three-Batter Minimum	—	Rules & Regulations	Requires relief pitchers to face at least three batters or finish an inning before being replaced, barring injury.	Introduced to curb excessive matchup pitching changes and speed up late innings.
Challenge System	—	Rules & Regulations	Allows managers a limited number of video review challenges to overturn umpire calls on the field.	Each club starts with one challenge per game and retains it if the call is overturned.
Obstruction	—	Rules & Regulations	When a fielder without the ball impedes a runner's progress, the runner is awarded the base they would have reached.	Often occurs on rundowns or when catchers block the plate without possession under updated safety rules.
Batter Interference	—	Rules & Regulations	When the batter hinders the catcher or fielder during a play, resulting in the batter being called out and runners returning.	Includes stepping outside the batter's box on a steal attempt or contacting the catcher on a throw.
Force-Play Slide Rule	—	Rules & Regulations	Requires runners to make a bona fide slide on force plays to protect fielders and avoid malicious takeout attempts.	Established after the 2016 Chase Utley incident, violations result in both runner and batter-runner being called out.
Extra-Innings Runner	—	Rules & Regulations	Rule placing the previous inning's last batter as a runner on second base to start each extra inning.	Adopted to reduce marathon games and bullpen strain, especially during the regular season.
Active Roster	—	Roster Management	Group of 26 players eligible to play in a major league game during the regular season.	Clubs shuffle the active roster daily to balance bullpen coverage, bench bats, and matchups.
40-Man Roster	—	Roster Management	Club's protected list of players eligible for the major league, including those optioned to the minors.	Teams must add prospects to the 40-man roster to shield them from the Rule 5 Draft.
Option Year	—	Roster Management	Season in which a 40-man player can be moved between the majors and minors without clearing waivers.	A player typically has three option years; exhausting them requires clearing waivers before another demotion.
Injured List	IL	Roster Management	Roster designation removing an injured player from the active roster for 10, 15, or 60 days.	Players on the 60-day IL free a 40-man spot, while shorter stints keep the club from playing short-handed.
Designated for Assignment	DFA	Roster Management	Transaction giving a team seven days to trade, waive, or release a player while freeing a roster spot.	Common when a team needs to add a new acquisition or activate a player returning from the injured list.
Service Time	—	Roster Management	Accumulated days a player spends on the major league roster or injured list, impacting pay and free agency.	Teams sometimes option players late in the season to manage service time milestones and arbitration clocks.
Arbitration Eligibility	—	Roster Management	Status allowing players with three-plus years of service (or Super Two) to have salaries decided by arbitration.	Clubs and players exchange salary figures before a hearing if they cannot agree on a contract.
Super Two	—	Roster Management	Designation for players with at least two years of service and in the top 22% of time among that class, granting early arbitration.	Super Two status often delays promotions as teams attempt to avoid adding an extra year of arbitration.
Non-Roster Invitee	NRI	Roster Management	Player not on the 40-man roster who is invited to major league spring training camp.	NRIs can win roster spots with strong camps or serve as depth options kept in Triple-A.
Waiver Claim	—	Roster Management	Process by which a team acquires a player placed on waivers by another club, assuming his contract.	Claim priority is determined by reverse standings early in the season and by league record after July 1.
Taxi Squad	—	Roster Management	Group of extra players traveling with the team who can be activated quickly in case of injury or illness.	Became prominent during travel restrictions and remains useful for doubleheaders or emergency coverage.