This MedLibrary.org supplementary page on On-base percentage is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
In baseball statistics, on-base percentage (OBP) (sometimes referred to as on-base average [OBA], as the statistic is rarely presented as a true percentage) is a measure of how often a batter reaches base for any reason other than a fielding error, fielder's choice, dropped/uncaught third strike, fielder's obstruction, or catcher's interference (the latter two are ignored as either times-on-base (TOB) or plate appearances in calculating OBP). OBP is added to slugging average to determine on-base plus slugging (OPS). It first became an official MLB statistic in 1984.
Contents |
Overview
Traditionally, the best leadoff hitters in the game have high on-base percentages. The league average for on-base percentage has varied considerably over time; in the modern era it is around .340, whereas it was typically only .300 in the dead-ball era. On-base percentage can also vary quite considerably from player to player. The record for the highest career OBP by a hitter, based on over 3000 plate appearances, is .482 by Ted Williams. The lowest is by Bill Bergen, who had an OBP of .194.
Though extremely unlikely, it is possible for a player's on-base percentage to be lower than his batting average (H/AB). However very few players in major league history fall into this category, with the majority of them having under 100 ABs, as it requires having almost no walks or times hit by pitch, with a relatively higher number of sacrifice flies (e.g. if a player has 2 hits in 6 at bats with a sacrifice fly, his batting average would be .333, but his on-base percentage would be .286). An example of this phenomenon would be the Hall-of-Fame pitcher Phil Niekro's hitting statistics from 1982. In 87 AB he never walked, but had four sacrifice hits, leading to a Batting Average of .195 and an OBP of .193.
On-base percentage is calculated using this formula:
where
- H = Hits
- BB = Bases on Balls (Walks)
- HBP = times Hit By a Pitch
- AB = At bats
- SF = Sacrifice Flies
NOTE: Sacrifice flies were not counted as an official statistic until 1954. Before that time, all sacrifices were counted as sacrifice hits (SH), which included both sacrifice flies and bunts. Bunts (sacrifice hits since 1954), which would lower a batter's on-base percentage, are not included in the calculation for on-base percentage, as bunting is an offensive strategy – often dictated by the manager – the use of which does not necessarily reflect on the batter's ability and should not be used to penalize him. For calculations of OBP before 1954, or where sacrifice flies are not explicitly listed, the number of sacrifice flies should be assumed to be zero.
All-time leaders
bold is active player
Single Season Leaders
| # | Player | OBP2 | Team | Year(s) |
| 1 | Barry Bonds | .609 | San Francisco Giants | 2004 |
| 2 | Barry Bonds | .582 | San Francisco Giants | 2002 |
| 3 | Ted Williams | .551 | Boston Red Sox | 1941 |
| 4 | Babe Ruth | .542 | New York Yankees | 1923 |
| 5 | Barry Bonds | .529 | San Francisco Giants | 2003 |
| 6 | Babe Ruth | .528 | New York Yankees | 1920 |
| 7 | Ted Williams | .526 | Boston Red Sox | 1957 |
| 8 | Billy Hamilton | .517 | Philadelphia Phillies | 1894 |
| 9 | Barry Bonds | .515 | San Francisco Giants | 2001 |
| 10 | Ted Williams | .512 | Boston Red Sox | 1954 |
See also
Notes
- ^ "Career Leaders for On Base Percentage". Sports Reference, Inc. Retrieved on 2008-06-29.
- ^ "Single Season League Leaders for On-Base Percentage". Major League Baseball. Retrieved on 2008-01-08.
Wikipedia content modification information:
- This page was last modified on 9 November 2008, at 17:00.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "On-base percentage".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.

