Starting Pitcher Disabled List Analysis (2 of 3) by Jeff Zimmerman January 20, 2011 With the general overall numbers available from yesterday’s article, here’s each variable: Age I divided the data into several buckets, according to individual pitchers’ ages. Here are the results: Two numbers jump out. One interesting point is that the pitchers who continue to pitch as they get older have a lower BMI as a group. Another point is that there’s a large jump in Average Disabled List Expectancy (ADLE) from the age 27-to-28 bracket to the 29-to-30 bracket. Obviously, age is playing a part in DL stints. Body Mass Index – Height and Weight Proportions Scouts often refer to a player’s build when they talk about injury chances. Using height and weight information available from baseball-databank.org, I divided up the each pitcher’s BMI. Here are the results: Again, an age bias exists. Younger pitchers have, on average, higher BMIs than older pitchers. Also, the difference in BMI doesn’t appear to be caused by changes in height as height varies by only half an inch. Instead, the main cause of change in BMI from one pitcher to the next is weight — which goes from averaging 185 pounds to 241 pounds. The final interesting trend is that, as BMI increases, there is no real trend in ADLE. Country of Origin and School Attended For grins, I wanted to see if there are trends based on a player’s place of birth. Not much can be drawn from the data. Players from the United States and Latin America make up 95% of the pitchers, and their ADLE figures are almost identical. It’s pretty easy to say that you can’t put much stock into country-of-origin as a factor in DL stays. But what about players who attended college? I divided the pitchers into two groups: those who attended college, and those who did not. It appears that pitchers who went to college have a lower ADLE value — even though, as a group, they are a half-a-year older. That is all for today. Tomorrow, I will group begin combining all the preceding data to look at deeper trends.