MLB stat definition: Bill James Game Score

What is Bill James Game Score?

The noted sabermetrician designed a system as a simple way of measuring the effectiveness of a pitcher’s start.

Bill James Game Score

A pitcher starts with 50 points, gets a point for each out, two points for each innings completed after the fourth inning, and one point for a strikeout.

He is docked two points for each hit, four points for each earned run allowed, two points for each unearned run allowed and one point for each walk.

An average Game Score in a given season usually ranges from 49 to 50.

The way Game Score is calculated, nearly every start ends up scoring between 0 and 100, with occasional exceptions for extraordinarily good or bad pitching performances.

Leaders and trailers

The best Game Score in 2012 was Matt Cain’s 101 for his perfect game against the Houston Astros. Felix Hernandez’s perfect game rated second-best, a 99. The difference was that Cain struck out 14, two more than Hernandez.

Three Game Scores in 2012 rated below 0, led by A.J. Burnett’s -13 after he allowed 12 runs in 2 2/3 innings against the St. Louis Cardinals.

Less than one percent of Game Scores rated 90 and above. There were 150 Game Scores that rated an 80 or above (about one of every 16), meaning the average team had about five such starts last season.

Clayton Kershaw had the best average Game Score among those who qualified for the ERA title in 2012- 63.0. Rounding out the top five were Justin Verlander (62.7), R.A. Dickey (62.1), David Price (61.5) and Matt Cain (60.6).

Game Score can be found in every box score on ESPN.com. Seasonal leaderboards can be compiled using the Baseball-Reference Play Index.