For years, I have heard claims that some Major League Teams favor drafting pitchers who grew up in colder climates.
The reason?
Fewer months able to be spent outside likely means fewer competitive pitches thrown, fewer innings pitched, and perhaps less risk of cumulative stress to shoulders and elbows. Practicing pediatric sports medicine in almost too sunny Southern California (yes indeed, we desperately need rain) I commonly encounter young throwers who pitch most if not almost all months of the year.
Now, thanks to the recent study Is Tommy John Surgery Performed More Frequently in Major League Baseball Pitchers From Warm Weather Areas?, there might actually be some scientific confirmation to these concerns.
Based on rates of elbow medial ulnar collateral ligament (UCL) reconstruction (commonly known as Tommy John Surgery) in Major League pitchers who played high school baseball in warmer vs. colder climates (defined by latitude on map and mean average temperatures), those who grew up in the warmth were found to have a more frequent and earlier UCL reconstructions than players who grew up in the colder environments.
I also found another interesting finding that almost 2/3 of the Major League pitchers in the study pool from 1974 to June 1, 2014 were from colder climates, while by the definitions utilized of warmer vs. colder climates, almost 2/3 of the 73 total studied areas were in colder climates while only 23 of 73 areas were defined as warmer. This correlation does make sense from a general statistical model, but when considering that the warmer areas contain purported baseball hotbeds such as California, Florida, Texas and countries in the Caribbean, Central and South America, the 2/3 proportion coming from colder climates again might support the higher risk cumulative stress and injury in warmer, more possible year-round baseball climates. Perhaps hibernating from too much pitching is ultimately a protective and positive thing and not just another reason to complain about bad weather in certain regions.
The published results on Major League pitchers should not be directly correlated with injury risk to pitchers at the pre-high school, high school and even collegiate or minor league levels. However, if similar studies were conducted at those levels with comparison of UCL reconstruction rates between climates, I wouldn't be too surprised if the surgical frequencies were higher in warmer climates and possibly starting at younger ages as well.
The upshot of this post is not an endorsement or call for relocation to colder climates to foster a potential Major League Pitching career, but rather a cautionary tale that even in those fortunate and talented enough to pitch in the Major Leagues, the potential blessings to have year-round chances to competitively pitch must be tempered with the need for adequate rest and recovery. I think this need to not take undue advantage of virtually unlimited pitching opportunities does definitely correlate down to school-age and collegiate/minor league pitchers.
Once again, we are getting the message that more is not often better, especially in the long-term development of young athletes.