FanGraphs Library Stat Glossary

To find a particular statistic, use Ctr-F and type in the abbreviation or stat name that you are looking for.

Offense:

OBP – On-Base Percentage
OPS – On-base Plus Slugging
OPS+ – On-base Plus Slugging Plus
wOBA – Weighted On-Base Average
wRAA – Weighted Runs Above Average
UBR – Ultimate Base Running
wRC – Weighted Runs Created
wRC+ – Weighted Runs Created Plus
BABIP – Batting Average on Ball In Play
ISO – Isolated Power
HR/FB – Home Runs per Fly Ball rate
Spd – Speed Score
GB% – Ground ball percentage
FB% – Fly ball percentage
LD% – Line drive percentate
K% – Stikeout rate
BB% – Walk rate
O-Swing% – Outside-the-zone swing rate
Z-Swing% – Inside-the-zone swing rate
Swing% – Swing rate
O-Contact% – Outside-the-zone contact percentage
Z-Contact% – Inside-the-zone contact percentage
Contact% – Contact percentage
Zone% – Percentage of pitches within the zone
F-Strike% – First-pitch strike percentage
SwStr% – Swinging Stike percentage
wFB – Fastball runs above average
wSL – Slider runs above average
wCT – Cutter runs above average
wCB – Curveball runs above average
wCH – Change-up runs above average
wSF – Split-finger fastball runs above average
wKN – Knuckleball runs above average
wFB/C – Fastball runs above average per 100 pitches
wSL/C– Slider runs above average per 100 pitches
wCT/C – Cutter runs above average per 100 pitches
wCB/C – Curveball runs above average per 100 pitches
wCH/C – Change-up runs above average per 100 pitches
wSF/C – Slit-fingered fastball runs above average per 100 pitches
wKN/C – Knuckleball runs above average per 100 pitches

Defense:

rSB – Stolen Base Runs Saved runs above average
rGDP – Double Play Runs Saved runs above average
rARM – Outfield Arms Runs Saved runs above average
rGFP – Good Fielding Plays Runs Saved runs above average
rPM – Plus/Minus Runs Saved runs above average
DRS – Defensive Runs Saved runs above average
BIZ – Balls In Zone
OOZ – Balls Out Of Zone
RZR – Revised Zone Rating
CPP – Expected Catcher Passed Pitches
RPP – Catcher Blocked Pitches in runs above average
TZ – Total Zone
TZL – Total Zone with Location data
FSR – Fan Scouting Report
ARM – Outfield Arm runs above average
DPR – Double Play runs above average
RngR – Range runs above average
ErrR – Error runs above average
UZR – Ultimate Zone Rating
UZR/150 – Ultimate Zone Rating per 150 defensive games

Pitching:

ERA – Earned Run Average
WHIP – Walks and Hits per Innings Pitched
FIP – Fielding Independent Pitching
xFIP – Expected Fielding Independent Pitching
SIERA – Skill-Interactive ERA
tERA – True Runs Allowed
K/9 – Strikeout rate
BB/9 – Walk rate
K% – Strikeout percentage
BB% – Walk percentage
K/BB – Strikeout-to-Walk ratio
LD% – Line drive rate
GB% – Ground ball rate
FB% – Fly ball rate
HR/FB – Home runs per fly ball rate
BABIP – Batting Average on Balls In Play
LOB% – Left On Base percentage
ERA- – ERA Minus
FIP- FIP Minus
xFIP- – xFIP Minus
SD – Shutdowns
MD – Meltdowns
O-Swing% – Outside-the-zone swing rate
Z-Swing% – Inside-the-zone swing rate
Swing% – Swing rate
O-Contact% – Outside-the-zone contact percentage
Z-Contact% – Inside-the-zone contact percentage
Contact% – Contact percentage
Zone% – Percentage of pitches within the zone
F-Strike% – First-pitch strike percentage
SwStr% – Swinging Stike percentage
wFB – Fastball runs above average
wSL – Slider runs above average
wCT – Cutter runs above average
wCB – Curveball runs above average
wCH – Change-up runs above average
wSF – Split-finger fastball runs above average
wKN – Knuckleball runs above average
wFB/C – Fastball runs above average per 100 pitches
wSL/C– Slider runs above average per 100 pitches
wCT/C – Cutter runs above average per 100 pitches
wCB/C – Curveball runs above average per 100 pitches
wCH/C – Change-up runs above average per 100 pitches
wSF/C – Slit-fingered fastball runs above average per 100 pitches
wKN/C – Knuckleball runs above average per 100 pitches

Win Probability:

WPA – Win Probability Added
-WPA – Loss Advancement
+WPA – Win Advancement
RE24 – Run Above Average based on the 24 Base/Out States
REW – Wins Above Average based on the 24 Base/Out States
pLI – A player’s average LI for all game events
phLI – A batter’s average LI in only pinch hit events
PH – Pinch Hit Opportunities
gmLI – A pitcher’s average LI when he enters the game
inLI – A pitcher’s average LI at the start of each inning
exLI – A pitcher’s average LI when exiting the game
WPA/LI – Situational Wins
Clutch – How much better or worse a player does in high leverage situations than he would have done in a context neutral environment

WAR

Offensive

Batting – Park Adjusted Runs Above Average based on wOBA
Base Running –  Base running runs above average, includes SB or CS
Fielding – Fielding Runs Above Average based on UZR (TZ before 2002)
Replacement – Replacement Runs set at 20 runs per 600 plate apperances
Positional – Positional Adjustment set at +12.5 for C, +7.5 for SS, +2.5 for 2B/3B/CF, -7.5 for RF/LF, -12.5 for 1B, -17.5 for DH
Fld + Pos
RAR – Runs Above Replacement (Batting + Fielding + Base Running + Replacement + Positional)
WAR – Wins Above Replacement

Pitching

RA9-Wins – Wins Above Replacement calculated using Runs Allowed
BIP-Wins – BABIP wins above average
LOB-Wins – Sequencing in wins above average (calculated as the difference between RA9-Wins and WAR minus BIP-Wins)
FDP-Wins – BABIP and Sequencing wins above average, also the difference between RA9-Wins and WAR
RAR – Runs Above Replacement
WAR – Wins Above Replacement