|About the stats|
Over the course of his career, Art Mahaffey pitched 999 innings and made 360 plate appearances. Mahaffey was worth 7.4 Wins Above Replacement (7.7 as a pitcher and -0.4 as a hitter) and -2.6 Wins Above Average (-2.3 as a pitcher and -0.4 as a hitter).
After adjusting for length of schedule, catchers, and relief pitchers, the 7.4 WAR becomes 7.2 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 -2.6 WAA becomes 3.6 adjWAA.
Then, the adjWAR and adjWAA are combined, but with extra weighting given to adjWAA. This gives Mahaffey 13.7 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).
Art Mahaffey has a Hall Rating of 13, leaving him nowhere close to induction to the Hall of Stats.
Want even more detail about the formula? See the About page.