Tom Verducci released his “Verducci Effect” candidates this week, and Phil Hughes and Ivan Nova made the list. For those who are unfamiliar, Verducci has concluded that pitchers 25 years old and younger who see a workload jump of at least 30 innings in one season are at greater risk of injury than their peers. As I have said before, I do not find his conclusions compelling, for the following reasons:

1) His premise is obvious, and as Verducci himself notes, clubs 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. The idea that Verducci’s 30 IP threshold should be applied indiscriminately to all pitchers is facially ridiculous, and it seems obvious that the club has attempted to implement a system for establishing “safe” limits tailored to each pitcher. They clearly had a target for Hughes this season and Joba in 2009, and acted accordingly. As such, I see no real reason to be concerned about Phil’s workload. 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 two years ago, 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.

What do you think of the Verducci Effect?

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4 Responses to Verducci: Hughes and Nova Are Injury Risks

  1. DW says:

    Verducci forgot Hughes AA post season start in 06.

  2. oldpep says:

    I think Verducci likes to have something with a bit of intelligence like this attached to his name. I also think he realized he needed some numbers to keep his name linked with it, and came up with 30. I seriously doubt he’s done any research beyond that (and likely relied on other people’s work for even that.)
    There are so many variables (especially age 19 vs age 24, etc) that one single number couldn’t possibly apply to every pitcher under 25.

    • Disco says:

      Verducci takes that into account.

      When he digs deeper, he acknowledges that the Verducci effect may not be relevant depending on the age and size of the pitcher. On MLBN he said he isn’t going to worry about Hughes because he is older than he was, and has a strong, big frame.

  3. Disco says:

    It’s an okay tool for quick, glancing analysis.

    But pitches thrown is more telling and it all depends on the pitcher/context. Not all innings are created equal.

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