|About the stats|
Over the course of his career, Al Spalding pitched 2,886 innings and made 1,988 plate appearances. Spalding was worth 60.4 Wins Above Replacement (53.6 as a pitcher and 6.8 as a hitter) and 37.2 Wins Above Average (31.4 as a pitcher and 5.8 as a hitter).
After adjusting for length of schedule, catchers, and relief pitchers, the 60.4 WAR becomes 55.1 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 37.2 WAA becomes 25.8 adjWAA.
Then, the adjWAR and adjWAA are combined, but with extra weighting given to adjWAA. This gives Spalding 101.5 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).
Al Spalding has a Hall Rating of 95, making him close to the Hall of Stats borderline—but still on the outside.
Want even more detail about the formula? See the About page.