No Major League team employs, on its active 25-man roster, a left-handed throwing catcher. About 9 percent of people are lefties, and 63 men in baseball are listed as catchers, so you might expect that we’d find about 5 to 6 southpaw catchers.
But the absence of lefty catchers—that “discrepancy” of 5 men—doesn’t seem unusual. That is, it’s not hard to imagine that baseball clubs aren’t discriminating against left-handed catchers. But those same clubs surely discriminate against right-handed pitchers. More on that below.
Major League baseball’s website lists the active rosters of each team.1 They categorize players as Pitchers, Catchers, Infielders, or Outfielders.2 Players’ batting and throwing hands are listed, as are their heights and weights. From the later two, I was able to calculate Body Mass Index, a measure of fatness (higher numbers are fatter).
Differences between Leagues
The National League has 16 teams and the American League has 14. Is one League taller or fatter than another? No. American League players are on average 73.8 inches (just under 6 foot 2 inches), while National Leaguers are 73.7. The average weight is 211 pounds for both Leagues.
81% of National Leaguers are right-handed throwers, while 79% of American Leaguers are. Batting is about the same: 29% are left-handed, 62% are right-handed, and 9% are switch hitters.
The one big difference between the American and National League is the Designated Hitter rule. Whatever other effects this rule has, it doesn’t appear to show up in body types. Both Leagues have nearly the same distribution of biometric characteristics. Thus, below all League data is shown together.
Differences between Teams
There are some differences in height between teams. For example, the Dodgers have the shortest team at an average 72.2 inches, and the Rangers have the tallest at an average 74.5. The five shortest are: Dodgers 72.2; Royals 72.9; Astros 73.1; Giants 73.2; Pirates 73.2. The five tallest: Rangers 74.5; Cardinals 74.4; White Sox 74.3; Padres 74.3; Damn Yankees 74.2.
There are larger differences between weight. The Braves are the lightest at an average 205 pounds. The Rangers are the heaviest at 221 pounds. But don’t forget that the Rangers are also the tallest, so we’d expect them to be in the upper range of weight.
BMI controls for height in calculating fat. The Braves are still the skinniest with an average BMI of 26.5. And the Rangers are still the fattest with an average BMI of 28.0. The five skinniest teams: Braves 26.5; Diamondbacks 26.6; America’s Tigers 26.6; Rays 26.7; Athletics 26.8. The five fattest: Rangers 28.0; Nationals 27.9; Blue Jays 27.9; Astros 27.9; Marlins 27.9.
“Obesity” is typically defined as having a BMI of 30 or greater. “Overweight” is 25 to 30. With these definitions, 9.7% of Major League players are obese, and 77.3% are overweight! That is, 87% are overweight or obese. Since these men are all highly paid athletes, these results shows the severe limitations of BMI as a measure of “ideal” weight. Yes, this is the same measure your government will be using to justify new taxes on soda pop and so forth.
Differences between Positions
The largest differences in physical characteristics are between field Positions. We started by learning that there are no left-handed throwing Catchers in Major League Baseball. 94% of Infielders are righties, but only 69% of outfielders and 73% of Pitchers are.
Finding a higher proportion of left-handed Pitchers than there are left-handed people in the general population is not surprising to anybody that follows baseball. But learning of the high proportion of lefties among outfielders might be. Part of this discrepancy is because of the preference for left-handed batters and because most people bat with the same hand as they throw.
But that means that Infielders have the highest proportion of men who throw right but bat left. A breakdown of who bats left: 13% of Catchers, 24% of Infielders, 46% of Outfielders, and 28% of Pitchers. Of course, the pitching statistic is thrown off because pitchers don’t bat in the American League. About 1 out 5 Catchers and Infielders are switch hitters, but only 9% of Outfielders and 1% of Pitchers are.
Differences between Height & Weight for Positions
There were no differences, on average, between height and weight for handedness, but there were differences in height and weight for Position.
Catchers and Pitchers are the heaviest members of any team, with an average 215 pounds. Outfielders come in at 209 pounds, and Infielders are the lightest at 204 pounds. BMI still puts Catchers on top with 28.7; followed now by Infielders and Outfielders at 27.2. Pitchers are the skinniest at an average 27.0. The differences between weight and BMI must mean there are large differences in height.
There are. This picture shows the frequency of heights for each position. Infielders have the broadest distribution; meaning, their heights are all over the place except among the tallest. Catchers are 72.6 inches on average, with only narrow departures from the mean figure. Outfielders are a full inch taller at 73.5 inches on average.
As expected, Pitchers are the tallest men on the team: an average 74.7 inches. No other Position fields a man taller than 79 inches except Pitchers, which see quite a few men over this 6 foot 7 inch mark. But Pitchers are also among the shortest men on the team. Thus, this picture proves that details can be lost when examining only the averages.
Happy Opening Day everybody.
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1 I accessed the data on 4 April 2010. At that time, there was some incompleteness on MLB.com, in the sense that several teams still listed more than 25 men, and one (Phillies) listed only 24. I supplemented MLB.com’s data with that from the site Altius Directory. When the MLB site had too many men, I used the Altius data to see which players’ salaries were listed as either “$0” or “N/A”. I marked those men as “Deletes” and removed them from the analysis. For the missing Phillies man, I used Altius to discover which pitcher had a non-zero salary who was not listed on MLB.com. The data file I used can be downloaded here.
2 Some, but not all, American League teams listed “Designated Hitter” as a separate position. I categorized all these men as “Outfielders” as that is the most likely field position they would be called upon to play.