What is On Base Percentage?
It is intended to be a more accurate representation of a batter’s ability to get on base than their batting average – as it includes statistics such as the number of times they have been walked or hit by a pitch, which are normally not included in statistics that rely only on “at bats”.
How to calculate OBP
On Base Percentage (OBP) = (hits + walks + hit by pitch) / (at bats + walks + hit by pitch + sacrifice flies)
32 hits + 7 walks + 2 hit by a pitch is 41.
127 at bats + 7 walks + 2 hit by a pitch + 3 sacrifice flies is 139.
41 divided by 139 is 0.295
Therefore, the batter’s on base percentage is 0.295.
What qualifies as a hit?
If the batter (or runner) attempts another base and is caught out, they are still credited with the hit as long as they have reached 1st base.
What qualifies as a walk?
What qualifies as a “hit by pitch”?
What qualifies as a sacrifice fly?
If the batter is put out because a fielder catches the ball on the fly, an a runner who is already on base scores on the play, it counts as a sacrifice fly.
It should be noted that sacrifice bunts do not count against a batter’s calculation for on-base percentage like sacrifice flies are.
What qualifies as an “At Bat”?
- The batter being hit by a pitch
- Sacrifice fly or sacrifice hit
- Base on balls
- Inning ends while still at bat
- The batter is replaced by another hitter before the turn is completed
- Wikipedia – On Base Percentage
- Wikipedia – Hit (Baseball)
- Wikipedia – At bat
- Wikipedia – Base on Balls
- Wikipedia – Hit by Pitch
- Wikipedia – Sacrifice Fly
- Wikipedia – Sacrifice Bunt
- Major League Baseball – Official Rules: 10.01 – The Rules of Scoring
- ESPN – MLB Statistics – Batting
- Baseball-reference.com – Career Leaders for OBP
- NCAA – Official Baseball Statistics Rules
- NCAA – Official Softball Statistics Rules
- NCAA – The Official NCAA Baseball and Softball Scorebook
- NFHS – Statistician’s Manual
- International Baseball Federation – Scoring Manual
Baseball Statistics Calculators
- At Bats per Home Run (ABHR)
- Batting Average (BA)
- Batting Average on Balls in Play (BABIP)
- Walks per 9 Innings (BB/9)
- Walk to Strikeout Ratio (BB/K)
- Batting Park Factor (BFP)
- Component ERA (CERA)
- Defense Independent Component ERA (DICE)
- Earned Run Average (ERA)
- Equivalent Average (EqA)
- Fielding Percentage (FCPT)
- Fielding Percentage (FIP)
- Ground Ball / Fly Ball (GB/FB)
- Ground Outs / Fly Outs (GO/AO)
- Gross Production Average (GPA)
- Hits per 9 Innings (H/9)
- Innings Pitched per Game (IP/GS)
- Isolated Power (ISO)
- Strike to Walk Ratio (K/BB)
- Left on Base Percentage (LOB%)
- On Base Percentage (OBP)
- On Base Plus Slugging (OBPS)
- Opponents Batting Average (OBA)
- Plate Appearances per Strikeout (PA/SO)
- Power Finesse Ratio (PFR)
- Pythagorean Expectation
- Run Average (RA)
- Runs Created (RC)
- Range Factor (RF)
- Runs Produced (RP)
- Stolen Base Percentage (SB%)
- Slugging Percentage (SLG)
- Save Percentage (SV%)
- Total Average (TA)
- Total Bases (TB)
- Total Chances (TC)
- Times on Base (TOB)
- Walks and Hits per Inning Pitched (WHIP)
- Extrapolated runs (XR / XRR / XRB)