Game ScoreGSC

GSC stands for game score in baseball. Bill James’s single number for how good a start was, averaged over a pitcher’s starts. 50 is an ordinary start; 90 or more is a gem.

How GSC is calculated

Start at 50; +1 per out, +2 per inning completed after the 4th, +1 per strikeout; −2 per hit, −4 per earned run, −2 per unearned run, −1 per walk.

Kerry Wood’s 20-strikeout one-hitter in 1998 scored 105, the classic example of the top of the scale.

What counts as a good GSC?

Half of the 184 qualified MLB players in 2026 were at or below 51.2. Clearing 57.4 put a season in the top tenth of the league.

Median: 51.2
Top 10%: 57.4
Leader: 66.4

By position, the median was 51.6 for RP and 51.1 for SP.

Qualified: 10+ GS, non-zero, 2026 regular season.