|About the stats|
Over the course of his career, Sandy Koufax pitched 2,324 innings and made 858 plate appearances. Koufax was worth 48.8 Wins Above Replacement (53.1 as a pitcher and -4.2 as a hitter) and 26.4 Wins Above Average (30.6 as a pitcher and -4.2 as a hitter).
After adjusting for length of schedule, catchers, and relief pitchers, the 48.8 WAR becomes 49.7 adjWAR. Then, WAA is adjusted by ignoring negative seasons (thus, truly capturing a player’s peak seasons) and making similar adjustments for catchers and relief pitchers. After these adjustments, the 26.4 WAA becomes 32.5 adjWAA.
Then, the adjWAR and adjWAA are combined, but with extra weighting given to adjWAA. This gives Koufax 108.2 wWAR. wWAR is then converted to Hall Rating. A Hall Rating of 100 represents the Hall of Stats borderline (similar to OPS+ or wRC+, where 100 represents league average).
Sandy Koufax has a Hall Rating of 102, making him a member of the Hall of Stats—but one who sits very close to the borderline.
Want even more detail about the formula? See the About page.