Stuff is an interaction between velocity, pitch usage, pitch movement, and change of velocity. Previous articles on the development of the stuff equation have found that it is significantly correlated with both K/9, WAR, and xFIP/ERA. The benefit of using the Stuff metric, is you could theoretically look at a pitcher’s arsenal in a bullpen session, and with the use of radar guns and spin trackers, could calculate their stuff. This has implications for both scouting, and rehabilitation.


Welcome back from the All Star break. Consider this the Bossman Junior of Stuff reports. Starting Pitchers Without a doubt, Aaron Sanchez has established himself as one of the finest pitchers in Major League Baseball; by all metrics, he is elite. Since starting the Stuff report, he has not dropped below the “Elite line” of […]