J.C. Bradbury examines the Verducci Effect and finds no evidence for its existence.

The results do not bode well for the Verducci Effect. Pitchers who were predicted to decline actually improved. One potential problem with this study is that pitchers who pitched no innings at all in a season were not included; however, I think this bias is slight since this number is small, as even injured pitchers normally get in a few innings every season. Frankly, this is about as quick and dirty as you can get with a test; but, it’s a starting point, and I’d like to see others examine the effect further. While appreciate the intuition behind the Verducci Effect, I don’t see much evidence for it.

J.C. does use minor league innings from the prior season as well, which I don’t believe Tom Verducci does. That, I suppose, could make a difference as to which pitchers are being measured in which group.

Jeremy Greenhouse uses the new injury database to examine the Verducci Effect in more detail. His results are not cut and dried. Tom Verducci released his list of pitchers to watch as well. Joba Chamberlain makes the list, despite the Yankees best efforts to limit his workload.