Major League Baseball Players are Overweight

Andrew Hahn

The third game of the 2018 World Series was an epic, with the 18-inning contest going down in history as the longest World Series game ever, breaking the previous record of 14 innings. Unfortunately, even the most loyal fan probably had already fallen asleep before Los Angeles’s Max Muncy belted his walk-off home run to trim the Boston advantage to 2 games to 1 in the series. However, if the casual sports fan watched the first half of the 7 hour 20-minute game, he witnessed a pitching duel that left the game tied 1-1 after 9 innings. He would have missed the historic finish of the game but may have noticed something that may be interesting to think about. The starting pitchers, Walker Buehler (Dodgers) and Rick Porcello (Red Sox), appeared thinner than virtually all of the batters that they faced.

Buehler, the rookie sensation for the Dodgers, is rather slim for a professional athlete, standing 6 feet 2 and weighing only 175 pounds. However, his Body Mass Index (BMI) is 23, which places him within the normal range (18.5-24.9) for adult males. Boston’s third game starter, Rick Porcello, who also appears thin, is technically overweight with a BMI of 25 (6 feet 5, 209 pounds). However, it should be noted that athletes are often classified as “overweight” by BMI measurements because muscle weighs more than fat. Therefore, baseball player’s BMI may not be an indication of his fitness, but how much muscle mass he has. With that assumption, starting pitchers and batters can be compared for their relative muscle mass.

The average BMI of MLB starting pitchers who have the 10 best ERA for 2018 regular season is 25.5. Of these 10 elite pitchers, Houston’s Gerrit Cole has the highest BMI (28), and the slim Jacob deGrom has the lowest BMI (22) because the 6 foot 4 inch Met weighs only 180 pounds. As a comparison, top 10 relief pitchers from 2018 (based on the number of saves) have an average BMI of 27.3, indicating that relief pitchers are either more muscular or pudgier than starting pitchers. This would appear logical as closing pitchers tend to throw harder and do not need as much stamina as starters.

When selecting 10 elite hitters to compare to the 10 elite starting pitchers, the BMI of the players with the 10 highest batting averages from 2018 was calculated. The results show that the average BMI of the hitters was 27.2, which is 1.7 points higher than the pitchers. The difference between the pitchers and hitters is slightly more pronounced when evaluating power hitters. Specifically, the top 10 home run hitters from 2018 have an average BMI of 27.7. It seems logical that long-ball hitters are more muscular than pitchers, but one may be surprised to find that home-run hitters and players with high batting averages have similar BMI’s. The exception to the observation that pitchers are leaner than hitters is for batters who can steal bases. The top ten stolen base leaders for 2018 have an average BMI of 25.6, almost identical to the top starting pitchers. It’s not surprising that leaner athletes are quicker on the bases, but pitchers and base stealers having similar body build may be an unexpected observation.

Analysis of MLB players shows that the majority of these athletes are “overweight” with BMI’s greater than 25. However, this is due to the limitation in the use of the BMI for athletes who tend to be more muscular than the couch potato watching them perform. What’s interesting is that successful starting pitchers have relatively lower BMI’s than elite hitters. This fact suggests that muscle mass is not as important for pitchers, and other attributes such as flexibility and fitness may be more useful.