THE BOOK--Playing The Percentages In Baseball

Thursday, October 11, 2007

YAE

I’ve been tracking the YAE for about a decade now. ...young pitchers should not have their innings workload increased by more than 25 or 30 innings per year. The body cannot easily withstand being pushed so far behind its previous capacity for work, at least not without consequences. Typically, those consequences occur the next season, not the year in which the body is pushed. When I’ve looked at major league pitchers 25-and-younger who were pushed 30 or more innings beyond their previous season (or, in cases such as injury-shortened years, their previous pro high), I’ve been amazed how often those pitchers broke down with a serious injury the next season or took a major step backward in their development. (The season total includes all innings in the minors, majors and postseason. )

While I have no doubt that Verducci is somewhat right, I’m not sure the magnitude of it. 

I personally have said that a pitcher’s workload should increase by 200 pitches (50 batters, 13 IP) per year, until he’s 24 or 25. But, it’s really based on a gut feel and anectodal (Earl Weaver) evidence.  It would be interesting to see the extent of what Verducci claims is true.  For example, if you look at all under-25 pitchers who faced over 800 batters (minors, majors, playoffs) in year x, and split them up into: “faced 600 or fewer in year x-1 and x-2”, “faced over 800 in year x-1 or x-2”, “the rest”, what are the injury rates and performance differences in year x+1?