Game Score

Definition

Game Score measures a pitcher's performance in any given game started. Introduced by Bill James in the 1980s and updated by fellow sabermetrician Tom Tango in 2014, Game Score is presented as a figure between 0-100 -- except for extreme outliers -- and usually falls between 40-70.

A Game Score of 50 is considered "average," while a Game Score of 40 is deemed to be "replacement level." Game Scores in the 80s and 90s are widely regarded as impressive, and scores of at least 100 are exceptionally rare. Using Tango's formula, which is the version displayed on MLB.com, only nine of the 4,858 games started in 2015 resulted in Game Scores of 100-plus.

A Game Score is derived by factoring the quality (based on runs, hits, HR, walks, strikeouts) and quantity (innings) of a starting pitcher's performance

Although James' and Tango's Game Score formulas lie in great parallel, they also diverge in ways that cause Tango's version to be slightly more linked to a pitcher's talent level. In the updated version, the following changes were made:

• A baseline score was moved from 50 to 40. This change prevents very short outings from being calculated as near average. (Ex. With a 50-score baseline, a starting pitcher could strike out the first batter of the game and be removed to record a Game Score of 52 -- above average. In reality, though, the starting pitcher being lifted after one out puts the team in a highly unfavorable position.

• A penalty for home runs allowed was implemented. Home runs allowed was not part of the initial formula -- created using the official line score in a box score -- despite their significant impact on a team's chances of victory.

• The penalty for a walk allowed was doubled from -1 to -2, to be in line with the penalty for a non-homer hit (single, double, triple). Although a non-homer hit is more impactful than a walk, both events are viewed equally when determining a player's talent level.

The formula

Game Score formula (created by Bill James)

  • Start with 50 points
  • Add 1 point for each out recorded (or 3 points per inning)
  • Add 2 points for each inning completed after the fourth
  • Add 1 additional point for every strikeout
  • Remove 2 points for each hit allowed
  • Remove 4 points for each earned run allowed
  • Remove 2 points for each unearned run allowed
  • Remove 1 point for each walk allowed

Game Score formula (updated by Tom Tango)

  • Start with 40 points
  • Add 2 points for each out recorded (or 6 points per inning)
  • Add 1 additional point for every strikeout
  • Remove 2 points for every walk allowed
  • Remove 2 points for every hit allowed
  • Remove 3 points for every run allowed (earned or unearned)
  • Remove 6 additional points for every home run allowed
Example

Watch: Max Scherzer no-hits the Mets to record a Game Score of 109 using the Tango formula (104 with the James formula).

Why it's useful

Game Score allows for a quick assessment of a particular pitcher's performance, simply by looking at one, easy-to-understand number. Furthermore, Game Score correlates strongly with winning percentage, so that a pitcher with an average Game Score of 60 can be expected to win approximately 60 percent of the time.

Fantasy advantage

A pitcher with a higher average Game Score -- particularly using the Tango method -- is slightly more likely to post stats beneficial to fantasy players in the future.