There has been much discussion in recent years concerning the "Verducci Effect" which states (more or less) that pitchers of age 24 or less who increase their innings pitched by 35 or more are subject to injury/diminished performance in the next year.  The annectdotal evidence for this seems strong.  On the other hand, there have been no real studies to quantify if the "effect" is large or if it even exists.  Since Jon Lester had essentially the largest innings increase of all eligible pitchers last year, I was quite interested to follow his and other potential Verducci victims during the year. Especially since Lester's early struggles were often linked in the press to the abuse he took over last year's long season.

Since this more or less marks the midway point of the season, I thought it might be interesting to look at this year's group of potential pitchers suffering from the Verducci effect.  I will look at the seven pitchers identified in Peter Bendix's Beyond the Boxscore article:

http://www.beyondtheboxscore.com/2009/1/5/709161/verducci-effect-update-7-r

These pitchers are

a)Jon Lester

b)Cole Hamels

c)Chad Billingsley

d)John Danks

e)Mike Pelfrey

f)Tim Lincecum

g)Jair Jurrjens

In looking at this group, we will compare their FIPs this and last year, so as not to bias (or at least limit bias of) outcomes based on possible random variation/defensive issues and the like.

a)Lester: Jon Lester has shown no signs of the Verducci effect.  Lester's FIP is a remarkably low 3.22 (among the best in the AL) and his K rates are up substantially. Despite the lingering effects of residual bad luck (his BAPIP is still a high .342), Lester has lowered his ERA to 3.87.  He is among the handful of best starters in the AL at this stage.

b)Hamels: Cole Hamels has struggled a bit with injury. While his ERA is significantly higher than last year (4.87 vs 3.09) his FIP is remarkably similar (3.90 vs 3.72). Hamels' FIP and BAPIP (.348 in 2009 vs .270 in 2008) suggest that his bloated ERA is largely beyond his control.

c)Billingsley: Chad Billingsley is almost the identical pitcher this year compared to last both in traditional metrics (ERA 3.38 vs 3.14) and FIP (3.56 vs 3.35).

d)Danks:  John Danks has seen a slightly diminished numbers (FIP of 3.93 vs. 3.44) but he has still pitched decently.  His FIP difference represents the largest negative amount of the group.

e)Pelfrey: By FIP Mike Pelfrey is essentially the same pitcher this year as last.

f)Lincecum: No problems here. Tim Lincecum is the most dominant pitcher in baseball, and sports a FIP a full 0.61 points lower than in his Cy Young winning year.

g)Jurrjens:  Jair Jurrjens' FIP is basically the same this year as last.

Amazingly, the annectdotal evidence *against* the Verducci effect are even stronger this (half) year than the 2008 evidence in favor of the effect.  All of these guys have been good this year, and none have serious health issues.  Hamels seems to have suffered the most, but the aggregate FIP of the pitchers listed above is actually lower this year than it was last year.  While statements like "Still, the results are convincing, and Verducci writes of similar results from past seasons as well" (from Bendix's article) seem sensible, the evidence so far this year strongly suggests that the correlation is overblown.  Either way, perhaps it is time that a serious (as opposed to superficial) look into this putative effect is performed.