## Team

- Pythagorean Expectation – where win percentage “should” be based only on runs for and against. May be an indicator of when a team is due for a winning or losing streak.

## Batting

- At Bats per Home Run (ABHR) – The number of at bats a player needs to create one home run.
- Batting Average (BA) – The percentage of a player’s at bats that result in a hit.
- Batting Average on Balls in Play (BABIP) – A modification of batting average.
- Walk to Strikeout Ratio (BB/K)
- Park Factor (BPF) – Helps compare batting factors among different parks and leagues.
- Equivalent Average (EqA) – An alternative to Batting Average (BA) that adjusts for park and league factors. Also known as True Average (TAv).
- Ground Ball / Fly Ball (GB/FB) – The ratio of ground to fly balls. Helps determine whether the ball will be hit high or low. Can also be used as a pitching metric.
- Ground Outs / Fly Outs (GO/AO) – The ratio of ground outs to fly outs (air outs). Similar to GB/FB.
- Gross Production Average (GPA) – A batting metric that combines on base and slugging percentages. It is an alternative to OBPS.
- Home Runs per At Bat (HR/AB) – The number of home runs created for each at bat.
- Isolated Power (ISO) – Isolates slugging average from batting average to show how many bases a batter hits for.
- On Base Percentage (OBP) – The percentage of times a batter gets on base to the number of times they have a chance to.
- On Base Plus Slugging (OBPS) – A mix of OBP and SLG. It combines both the chance of getting on base with the number of bases a batter typically earns.
- Plate Appearances per Strikeout (PA/SO) – How frequently a batter strikes out.
- Runs Created (RC) – A measurement of how many runs a hitter creates.
- Runs Produced (RP) – Another measurement of how many runs a hitter creates.
- Stolen Base Percentage (SB%) – How successful a runner is at stealing bases.
- Slugging Percentage (SLG) – Similar to batting average, but including the total number of bases earned.
- Total Average (TA) – The a mix of positive and negative actions.
- Total Bases (TB) – The total number of bases a batter has hit for.
- Times on Base (TOB) – The number of times a player has been on base.
- True Average (TAv) – An alternative to Batting Average (BA) that adjusts for park and league factors. Also known as Equivalent Average (EqA).
- Extrapolated Runs (XR / XRR / XRB) – Estimates the number of runs each batter contributes to their team.

## Fielding

- Fielding Percentage (FCPT) – a fielder’s number of putouts and assists in comparison to the total number of opportunities for putouts and assists.
- Range Factor (RF) – The average number of outs and assists a fielder produces for each regulation game.
- Total Chances (TC) – The total number of plays a defensive player has participated in.

## Pitching

- Batting Average Against (BAA) – The batting average of all hitters who have faced a specific pitcher. Also known as opponent’s batting average (OBA).
- Component Earned Run Average (ERC) – A modified ERA statistic. It arrives at a pitcher’s performance from more than just runs allowed.
- Defense Independent Component ERA (DICE) – An ERA statistic that is modified to remove the performance of the fielding team.
- Earned Run Average (ERA) – The most popular pitching statistic. The number of runs a pitcher allows per regulation game.
- Fielding Independent Pitching (FIP) – A pitcher’s performance independent of the defense team.
- Ground Ball / Fly Ball (GB/FB) – The ratio of ground to fly balls. Helps determine whether the ball will be hit high or low. Can also be used as a batting metric.
- Ground Outs / Fly Outs (GO/AO) – The ratio of ground outs to fly outs (air outs). Similar to GB/FB.
- Hits per 9 Innings (H/9) – Similar to ERA but for hits.
- Innings Pitched per Game (IP/GS) – The number of average innings a pitcher pitches for each game start.
- Left on Base Percentage (LOB%) – The average number of runners a pitcher leaves on base at the end of an inning.
- Opponents Batting Average (OBA) – The batting average of all hitters who have faced a specific pitcher. Also known as batting average against (BAA).
- Power Finesse Ratio (PFR) – The ratio of strikes and walks produced by a pitcher to the number of innings pitched.
- Run Average (RA) – Similar to ERA. It includes all runs against, including unearned runs.
- Save Percentage (SV%) – The percentage of saves to save chances.
- Strike to Walk Ratio (K/BB) – How frequently a pitcher strikes out a batter vs how frequently they walk them.
- Walks and Hits per Inning Pitched (WHIP) – A measurement of how frequently a pitcher allows walks and hits.
- Walks per 9 innings (BB/9) – The ratio of walks for each strike.