Basic and Advanced Stats
BASIC STATS
Pitching
EARNED RUN AVERAGE (ERA) = 9 x earned runs / innings pitched
Earned run average represents the number of earned runs a pitcher allows per nine innings, with earned runs being any runs that scored without the aid of an error or a passed ball. If a pitcher exits a game with runners on base, any earned runs scored by those runners will count against him.
GROUNDOUT-TO-FLYOUT RATIO (GO/AO) = Dividing the total number of ground balls converted into outs (not including bunts), by the total of all fly balls converted into outs
QUALITY START (QS)
A starting pitcher records a quality start when he pitches at least six innings and allows three earned runs or fewer.
SAVES (SV)
A relief pitcher recording a save must preserve his team's lead while doing one of the following:
- Enter the game with a lead of no more than three runs and pitch at least one inning.
- Enter the game with the tying run in the on-deck circle, at the plate or on the bases.
- Pitch at least three innings.
SAVE PERCENTAGE = Dividing a pitcher's total number of saves by his total number of save opportunities
Save percentage represents the percent of time a pitcher records a save when given a save opportunity.
WALKS & HITS PER INNING PITCHED (WHIP) = Sum of a pitcher's walks and hits, divided by his total innings pitched
The statistic shows how well a pitcher has kept runners off the basepaths
Offense
ON-BASE PERCENTAGE (OBP) = How frequently a batter reaches base per plate appearance
Times on base include hits, walks and hit-by-pitches, but do not include errors, times reached on a fielder's choice or a dropped third strike.
ON-BASE PLUE SLUGGING (OBS) = Add on-base percentage and slugging percentage
SLUGGING PERCENTAGE (SLG) = (1B + 2Bx2 + 3Bx3 + HRx4)/AB (# of Singles + 2 x # of Doubles + 3 x # of Triples + 4 x # of Homeruns) / At Bats
Total number of bases a player records per at-bat; does not include walks and hit-by-pitches.
Defense
FIELDING PERCENTAGE (FPCT) = The total number of putouts and assists by a defender, divided by the total number of chances (putouts, assists and errors)
ADVANCED STATS
Pitching
ADJUSTED EARNED RUN AVERAGE (ERA+) = League ERA, adjusted for park factors x 100 / ERA
Takes a player's ERA and normalizes it across the entire league. It accounts for external factors like ballparks and opponents. It then adjusts, so a score of 100 is league average, and 150 is 50 percent better than the league average.
FIELDING INDEPENDENT PITCHING (FIP) = ((HR x 13) + (3 x (BB + HBP)) - (2 x K)) / IP + FIP constant ("FIP constant" puts FIP onto the same scale as the entire league's ERA)
FIP is similar to ERA, but it focuses solely on the events a pitcher has the most control over -- strikeouts, unintentional walks, hit-by-pitches and home runs. It entirely removes results on balls hit into the field of play.
PITCHES PER INNING PITCHED (P/IP) = Divide a pitcher's total number of pitches thrown by his total number of innings pitched
Pitches per inning pitched is a tool used to evaluate how efficient a pitcher is at getting his outs.
STRIKEOUT TO WALK RATIO (K/BB) = Divide a pitcher's total number of strikeouts by his total number of walks
How many strikeouts a pitcher records for each walk he allows.
Offense
ON-BASE PLUS SLUGGING PLUS (OPS+) = (OPS / league OPS, adjusted for park factors) x 100
Takes a player's on-base plus slugging percentage and normalizes the number across the entire league. It accounts for external factors like ballparks. It then adjusts so a score of 100 is league average, and 150 is 50 percent better than the league average.
BATTING AVERAGE ON BALLS IN PLAY (BABIP) = (H - HR)/(AB - K - HR + SF)
Measures a player's batting average exclusively on balls hit into the field of play, removing outcomes not affected by the opposing defense (namely home runs and strikeouts).
WINS ABOVE REPLACEMENT (WAR) FOR POSITION PLAYERS = (The number of runs above average a player is worth in his batting, baserunning and fielding + adjustment for position + adjustment for league + the number of runs provided by a replacement-level player) / runs per win
Measures a player's value in all facets of the game by deciphering how many more wins he's worth than a replacement-level player at his same position.
Defense
DEFENSIVE EFFICIENCY RATIO (DER) = 1 - ((H + ROE - HR) / (PA - BB - SO - HBP - HR))
Evaluates team defense by finding out the rate of times batters reach base on balls put in play.