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Traditional-style baseball scorecard.

Baseball scorekeeping is the practice of recording the details of a baseball game as it unfolds. Professional baseball leagues hire official scorers to keep an official record of each game (from which a box score can be generated), but many fans keep score as well for their own enjoyment.[1] Scorekeeping is usually done on a printed scorecard and, while official scorers must adhere precisely to one of the few different scorekeeping notations, most fans exercise some amount of creativity and adopt their own symbols and styles.[2]


Sportswriter Henry Chadwick is generally credited as the inventor of baseball scorekeeping. His basic scorecard and notation have evolved significantly since their advent in the 1870s[3] but they remain the basis for most of what has followed.

Abbreviations and grammar

See also: Baseball fielding positions

Some symbols and abbreviations are shared by nearly all scorekeeping systems. For example, the position of each player is indicated by a number:

  1. Pitcher (P)
  2. Catcher (C)
  3. First baseman (1B)
  4. Second baseman (2B)
  5. Third baseman (3B)
  6. Shortstop (SS)
  7. Left fielder (LF)
  8. Center fielder (CF)
  9. Right fielder (RF)
  10. Rover or short fielder (used primarily in softball)

The designated hitter (DH), if used, is marked using a zero (0).


Scorecards vary in appearance but almost all share some basic features, including areas for:

Usually two scorecards (one for each team) are used to score a game.

Traditional scorekeeping

Scorecard for first ever MLB perfect game, by Lee Richmond, 1880. Abbreviations: A, B, C, for first, second and third, P and H for pitcher and catcher, S for shortstop, L, M, and R for left, center, and right field

There is no authoritative set of rules for scorekeeping. The traditional method has many variations in its symbols and syntax, but this is a typical example.

In the traditional method, each cell in the main area of the scoresheet represents the "lifetime" of an offensive player, from at-bat, to baserunner, to being put out, scoring a run, or being left on base.


When an out is recorded, the combination of defensive players executing that out is recorded. For example:

A vertically reflected K is the standard notation for a strikeout looking.

Reaching base

If a batter reaches first base, either due to a walk, a hit, or an error, the basepath from home to first base is drawn, and the method described in the lower-righthand corner. For example:


When a runner advances due to a following batter, it can be noted by the batting position or the uniform number of the batter that advanced the runner. This kind of information is not always included by amateur scorers, and there is a lot of variation in notation. For example:



Sample baseball scorecard from a game scored on August 8, 2000 at (then) Pacific Bell Park.
Sample baseball scorecard from a game scored on August 8, 2000 at (then) Pacific Bell Park.

The scorecard on the right describes the August 8, 2000 game between the Milwaukee Brewers and San Francisco Giants, played at Pacific Bell Park, in San Francisco.[5] The scorecard describes the following events in the top of the 1st inning:

One hard and fast rule of baseball scorekeeping is that every out and every time a baserunner advances must be recorded. The scoring can get a little more complicated when a batter who has reached base, is then "moved up" (advances one or more bases) by his own actions or by the actions of a hitter behind him. This is demonstrated in the Giants' first inning:

Stranded baserunners might be notated as being "LOB" (Left On Base) for that inning, with a number from 1-3 likely at the bottom of the inning column. For example, if two runners are left on base after the 3rd out, the scorekeeper might note "LOB:2", then at the end of the game calculate a total number of LOB for the game.

A more complicated example of scorekeeping is the record of the bottom of the 5th inning:

Project Scoresheet

Project Scoresheet was an organization run by volunteers in the 1980s for the purpose of collecting baseball game data and making it freely available to the public (the data collected by Major League Baseball was and still is not freely available). To collect and distribute the data, Project Scoresheet needed a method of keeping score that could be easily input to a computer. This limited the language to letters, numbers, and punctuation (no baseball diamonds or other symbols not found on a computer keyboard).


In addition to the new language introduced by Project Scoresheet, a few major changes were made to the traditional scorecard. First, innings of play are not recorded in a one-per-column fashion; instead all boxes are used sequentially and new innings are indicated with a heavy horizontal line. This saves considerable space on the card (since no boxes are left blank) and reduces the likelihood of a game requiring a second set of scorecards.

The second major change is the detailed offensive and defensive in/out system, which allows the scorekeeper to specify very specifically when players enter and leave the game. This is vital for attributing events to the proper players.

Lastly, each "event box" on a Project Scoresheet scorecard is broken down into three sections: before the play, during the play, and after the play. All events are put into one of these three slots. For example, a stolen base happens "before the play" because it occurs before the batter's at-bat is over. A hit is considered "during the play" because it ends the batter's plate appearance, and baserunner movement subsequent to the batter's activity is considered "after the play".


The language developed by Project Scoresheet can be used to record trajectories and locations of batted balls and every defensive player who touched the ball, in addition to the basic information recorded by the traditional method. Here are some examples:

In the "before the play" slot:

In "during the play" slot:

In the "after the play" slot:

Reisner Scorekeeping

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Project Scoresheet addressed a lack of precision in the traditional scorekeeping method, and introduced several new features to the scorecard. But while the Project Scoresheet language continues to be the baseball research community's standard for storing play-by-play game data in computers, the scorecards it yields are difficult to read due to the backtracking required to reconstruct a mid-inning play. Hence, despite its historical importance, the system has never gained favor with casual fans.

In 2002 Alex Reisner developed a new scorekeeping method that took the language of Project Scoresheet but redefined the way the event boxes on the scorecard worked, virtually eliminating the backtracking required by both Project Scoresheet and the traditional method. The system also makes it easy to reconstruct any mid-inning situation, a difficult task with the other two systems (for this reason it was originally promoted as "Situational Scorekeeping").


A Reisner scorecard looks like a cross between a traditional and Project Scoresheet scorecard. It has a diamond (representing the field, as in the traditional system) and a single line for recording action during and after the play (like Project Scoresheet's second and third lines). The diamond in each event box is used to show which bases are occupied by which players at the start of an at-bat. Stolen bases, pickoffs, and other "before the play" events are also marked on the diamond, so that one can see the "situation" in which an at-bat took place by simply glancing at the scorecard.

Computer Generated Scorecards

With the advent of online baseball event application programming interface feeds, it is now possible to have software generate and update a scorecard in real-time. Such scorecards can include a level of detail and precision which would not be practical for a human keeping score manually.

computer-generated scorecard
An example of a computer-generated scorecard[6]


  1. ^ "Keeping score". Archived from the original on 2005-07-01. Retrieved 2017-08-07.
  2. ^ "Ways to get on base". Archived from the original on 2009-12-12. Retrieved 2017-08-07.
  3. ^ Dickson, Paul. The Joy of Keeping Score. New York: Walker. ISBN 0-15-600516-6.
  4. ^ "Pickoff (PK)". Retrieved March 19, 2023.
  5. ^ "Milwaukee Brewers at San Francisco Giants, August 8, 2000". Baseball Reference. Retrieved 29 April 2013.
  6. ^ "Live Baseball Scorecards". Retrieved 2023-04-13.