Baseball Statistics Glossary
This glossary defines every one of the 53 statistical abbreviations used on Baseball Data Hub, grouped by batting, pitching, fielding, value and team statistics. Each entry gives the abbreviation, its full name and a one-sentence definition, and every stat column elsewhere on the site links to its row here. Batting average (AVG) is hits divided by at bats; ERA is earned runs allowed per nine innings; OPS is on-base percentage plus slugging percentage.
Data updated
Batting Statistics
| Abbreviation | Full name | Definition |
|---|---|---|
| G | Games Played | The number of games in which a player appeared, in any role. |
| AB | At Bats | Plate appearances that end in a hit or an out, excluding walks, hit-by-pitches, sacrifices and catcher interference. |
| PA | Plate Appearances | Every completed turn at the plate, including walks, hit-by-pitches and sacrifices. |
| R | Runs Scored | The number of times a player crossed home plate. |
| H | Hits | Times a batter reached base safely on a batted ball without an error or fielder's choice. |
| 2B | Doubles | Hits on which the batter reached second base. |
| 3B | Triples | Hits on which the batter reached third base. |
| HR | Home Runs | Hits on which the batter circled the bases and scored, almost always by clearing the outfield fence. Full explanation → |
| RBI | Runs Batted In | Runs that scored as a direct result of a batter's plate appearance. Full explanation → |
| SB | Stolen Bases | Bases taken on the pitch without the aid of a hit, walk, error or other advancing play. Full explanation → |
| CS | Caught Stealing | Failed stolen-base attempts in which the runner was put out. |
| BB | Walks (Bases on Balls) | Times a batter reached first base on four pitches outside the strike zone. Full explanation → |
| IBB | Intentional Walks | Walks issued deliberately by the pitching team. |
| SO | Strikeouts | For a batter, times retired on a third strike; for a pitcher, batters retired on a third strike. Full explanation → |
| HBP | Hit By Pitch | Times a batter was awarded first base after being struck by a pitch. |
| SH | Sacrifice Hits | Bunts on which the batter was retired but a runner advanced. |
| SF | Sacrifice Flies | Fly outs on which a runner scored from third base. |
| GIDP | Grounded Into Double Play | Ground balls that produced two outs on the same play. |
| TB | Total Bases | One base per single, two per double, three per triple and four per home run. |
| AVG | Batting Average | Hits divided by at bats. .300 is the traditional mark of an excellent hitter. Full explanation → |
| OBP | On-Base Percentage | How often a batter reaches base: (H + BB + HBP) divided by (AB + BB + HBP + SF). Full explanation → |
| SLG | Slugging Percentage | Total bases divided by at bats — a measure of power rather than frequency. Full explanation → |
| OPS | On-Base Plus Slugging | On-base percentage plus slugging percentage, the quickest single summary of offensive value. .900 or better is star-level. Full explanation → |
| wOBA | Weighted On-Base Average | An on-base rate that weights each way of reaching base by how many runs it is actually worth. Full explanation → |
| BABIP | Batting Average on Balls in Play | Batting average on balls hit into the field of play, excluding home runs and strikeouts. Full explanation → |
Pitching Statistics
| Abbreviation | Full name | Definition |
|---|---|---|
| W | Wins | Games credited to a pitcher whose team took a lead it never surrendered while he was the pitcher of record. Full explanation → |
| L | Losses | Games charged to the pitcher of record when the opposing team took a lead it never surrendered. |
| ERA | Earned Run Average | Earned runs allowed per nine innings pitched: (ER × 9) ÷ IP. The primary measure of pitching effectiveness. Full explanation → |
| IP | Innings Pitched | Outs recorded divided by three; ".1" and ".2" mean one and two extra outs. |
| GS | Games Started | Games in which the pitcher threw the first pitch for his team. |
| CG | Complete Games | Games a starter finished without relief help. |
| SHO | Shutouts | Complete games in which the pitcher allowed no runs. |
| SV | Saves | Games finished by a relief pitcher who protected a narrow lead without being the winning pitcher. Full explanation → |
| ER | Earned Runs | Runs that scored without the aid of an error or passed ball. |
| WHIP | Walks and Hits per Inning Pitched | Baserunners allowed per inning: (BB + H) ÷ IP. Under 1.00 is elite. Full explanation → |
| K/9 | Strikeouts per Nine Innings | Strikeouts recorded per nine innings pitched. Full explanation → |
| BB/9 | Walks per Nine Innings | Walks issued per nine innings pitched — a control measure. Full explanation → |
| FIP | Fielding Independent Pitching | An ERA-scaled estimate built only from strikeouts, walks, hit batters and home runs — the outcomes a pitcher controls without his defense. Full explanation → |
| BAOpp | Opponent Batting Average | The batting average opposing hitters compiled against the pitcher. |
Fielding Statistics
| Abbreviation | Full name | Definition |
|---|---|---|
| PO | Putouts | Outs a fielder recorded directly, such as catching a fly ball or tagging a runner. |
| A | Assists | Throws or deflections by a fielder that led to an out recorded by a teammate. |
| E | Errors | Misplays that allowed a batter or runner to advance when ordinary effort would have retired him. |
| DP | Double Plays | Plays on which the defense recorded two outs. |
| FPCT | Fielding Percentage | The share of chances a fielder handled cleanly: (PO + A) ÷ (PO + A + E). |
Value Statistics
| Abbreviation | Full name | Definition |
|---|---|---|
| WAR | Wins Above Replacement | An estimate of how many more wins a player was worth than a freely available replacement-level player at the same position. Full explanation → |
| PIV | Player Impact Value | Baseball Data Hub's own offensive metric: production measured against the league average of the player's own era, then adjusted for how often he actually played. Full explanation → |
| Pitcher PIV | Pitcher Player Impact Value | The pitching counterpart to PIV: run prevention relative to the league average of the pitcher's own era, adjusted for workload. |
| OPS+ | Adjusted OPS | OPS rescaled so that 100 is league average for that season and park; 150 means 50% better than average. |
| ERA+ | Adjusted ERA | ERA rescaled so that 100 is league average for that season and park; higher is better. |
Team Statistics
| Abbreviation | Full name | Definition |
|---|---|---|
| Win% | Winning Percentage | Wins divided by games decided. |
| GB | Games Back | How far a team trailed the division or league leader. |
| RS | Runs Scored (team) | Total runs a team scored across the season. |
| RA | Runs Allowed | Total runs a team allowed across the season. |
Where these numbers come from
Every statistic on this site is computed from the season rows shown on the same page. See Data sources & methodology for the source of each dataset, how often it refreshes, and the known gaps.
Baseball Statistics: Frequently Asked Questions
- What does OPS mean in baseball?
- OPS is on-base percentage plus slugging percentage. It is the quickest single summary of a hitter's offensive value; .900 or better is star-level.
- What does ERA stand for?
- ERA stands for earned run average — the number of earned runs a pitcher allows per nine innings pitched, calculated as (earned runs x 9) divided by innings pitched.
- What is WHIP in baseball?
- WHIP is walks and hits per inning pitched: (walks + hits) divided by innings pitched. Under 1.00 is elite.
- What is a good batting average?
- A .300 batting average is the traditional mark of an excellent hitter. League average has generally run between .250 and .270 in the modern era.
- What is PIV?
- PIV (Player Impact Value) is Baseball Data Hub's own offensive metric. It measures production against the league average of the player's own era, then adjusts for how often he actually played.