The Flaws of the Verducci Effect

I recently received an email asking me why I ignored Tom Verducci’s recent article on pitcher workloads and his highlighting of Joba Chamberlain as a pitcher at risk in 2010. I felt that response would be better served by a full post. There are a number of reasons for my disinterest:

1) His premise is obvious, and the Yankees are aware of it. The idea that overworking young pitchers can lead to injuries down the road is not a Tom Verducci original. Medical professionals have been making similar suggestions for years, and teams like the Yankees have paid attention. They clearly had a target for Joba this season, and acted accordingly. I see no reason to be concerned. This is not an appeal to authority or a suggestion that the Yankees are always right, simply an acknowledgement that Verducci’s finding are far from an exact science (which he concedes), which leads me to my second point.

2) His findings are anecdotal. While he takes an accounting of his results each year, the reality is that his study is generally incomplete in terms of evidence. David Gassko tested the premise and found that the data did not support, and may have been in conflict with, Verducci’s findings. Michael Salfino of SNY did a similar takedown last year, listing a number of issues with the study, including its ignorance of the concept of regression to the mean.

3) One major issue with the study is the inherent selection bias created by looking at pitchers with a large innings increase. Generally, a jump of that sort would be caused by one of two things: either an unexpected jump in performance which dictates increased use of the player, OR the player had injuries in prior seasons and was unable to build up innings properly. Both causes suggest that the player is more likely than others to see either some regression or a recurrence of injury.

These are my reasons for not paying much attention to the Verducci effect. Do you agree with them?

0 thoughts on “The Flaws of the Verducci Effect

  1. I tend to agree. Many columnists, even good ones, tend toward generalizations based on anecdote, and we know that the plural of anecdote does not data make. Like you, I prefer things to be at least reinforced by the findings resultant of more scientific analysis. As a coach and scout, yes, I do anecdotally see the potential for harm in jumping one’s innings dramatically from one year to the next, but the Yankees have done their best to make this a gradual process for Chamberlain. At some point, he’s going to have to pitch more, and there is nothing innate within Chamberlain to suggest that he will react poorly to this jump. Some people handle it well. Perhaps Joba’s decreased focus on fastball velocity and increased focus on pitch selection and command will make for a smooth transition into the 200 inning pitcher the Yankees are hoping for. I don’t think Verducci’s article was particularly novel or brilliant. He is not a Yankees writer, after all, so it’s not a knock on him to say that his piece isn’t novel with regards to Chamberlain. As a national writer, he isn’t tasked with tracking Joba Chamberlain’s progress month by month. It makes sense for him to write this, and it makes sense for us to yawn when we read it.

  2. eddieperez23

    I agree, as you cited everyone is now aware of the risk of sharp increases in workloads especially for young pitchers and have adjusted accordingly. So while Verducci’s analysis is far from comprehensive, I will give him credit for being the first mainstream baseball baseball scribe (that I’m aware of) to shine the light on this “risk guideline” for pitchers. That said his analysis has many holes and I trend to treat it as a “ceremonial” article. Something I read b/c I’ve been doing it for a decade, but nothing more.

  3. pete

    the biggest flaw in the “Verducci Logic” is that it says that because a lot of or even most pitchers who experienced workload increases of more than 30 innings over a previous high experienced dropoffs in performance or injuries the following year, we should assume that players who made that jump have injury risks or dropoff risks. In reality, every pitcher should be considered thoroughly for injury and regression risk, and while innings play a part, there are a multitude of factors that go into it. Equating innings totals to injury risk is on par with equating Wins to pitcher effectiveness. It can often be a solid summary, and the historical evidence suggests that there is generally a correlation, but just as wins are based on far too many external factors to be an accurate gauge, innings are also based on too many external factors.

    A team like the yankees has probably studied this harder, had access to more and better information, and consulted more expert opinions than any of us have. If I were a Reds fan, I’d be very worried. As a yankees fan, I’m no more worried about Joba getting hurt than I am AJ or Andy or Phil, and only slightly more than I am about CC and Javy, both of whom have shown extraordinary durability and consistency throughout their careers, thus seemingly reducing their injury risk. If any pitcher on the yankees gets injured this year, chances are it won’t be because the yankees screwed them over. It will be because they pitch for a living, and pitching itself is about as correlative to arm injury as innings totals are. And, in the case of Andy, it could also be a factor of age. But the yankees aren’t being stupid about this, so there really isn’t any need for us to worry more than we should for every pitcher.

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