This post has nothing directly to do with investment markets or tax strategy. However, the insights here, about how competitive pressures explain observed phenomena in baseball, might have analogues in the areas of markets and tax planning.
There are few activities more competitive, and the results of which are more public, than Major League Baseball. The competitive pressure of baseball explains why there are no left-handed catchers, and the many statistics available enable us to build the argument supporting this explanation.
If you follow baseball, you have probably noticed that there are no left-handed catchers in Major League Baseball. There is no rule against left-handed catchers. In fact, a lefty named Benny Distefano played three games behind the plate for the Pittsburgh Pirates in 1989.
To understand why there are essentially no left-handed catchers, it is natural to think about throwing mechanics, and field geometry. These factors explain why there are essentially no left-handed throwing third basemen, shortstops, or second basemen.
But, as I will argue, the throwing mechanics and field geometry theory does not explain the absence of left-handed catchers.
The primary defensive duty of infielders (other than first basemen) is to field ground balls, and throw to first. Approximately 30% of all outs recorded in recent years in MLB games have been from ground balls. Thus, it makes sense that these infielders would be selected, from among those who hit well enough, for their ability to field and throw to first efficiently.
For a third baseman, shortstop, or second baseman, the throw to first after fielding a groundball is almost always, by the geometry of the baseball field, an across-the-body throw to his left. It is much faster for a right-handed thrower to make these throws than it would be for a left-hander. This efficiency difference is so great that there are and have been essentially no left-hand-throwing second or third basemen, nor shortstops.
Left-Handed Pitchers Fielding
We can see the throwing dynamics in action when a left-handed pitcher fields a ground ball. If he has to go to his right to field the ball, he will usually spin all the way around to make the throw to first. Only when the ball is hit right to him so that he has plenty of time will he take the extra time required to reorient his body for a natural left-handed throw to first. If the ball is hit to his left, and he fields it, he’s usually close enough to first for a soft underhand toss to get the job done.
One of the beauties of baseball is that there are statistically significant numbers of so many different items of interest.
Pitcher put-outs on ground balls (so-called “1-3” putouts[1]) are well recorded, and documented by, among other things, left-handed or right-handed pitcher.
If our body-mechanics theory is correct, and it is faster for a right hander to make the throw to first, we should see this show up in the data comparing right-handed pitchers fielding ground balls to left-handed pitchers fielding ground balls.
The data support the body-mechanics hypothesis. Data from retrosheet (as reported by a ChatGPT search) show that right-handed pitchers record approximately double the number of 1-3 (baseball shorthand for “pitcher to first baseman”) putouts. These data from the 2022 season are in the box below:
| Pitcher Hand | 1–3 Putouts / 1000 BF |
| RHP | ~6.5 |
| LHP | ~3.1 |
In 2024, the league hit .250 against right-handers, and .245 against left-handers. This difference is statistically significant at the 5% level (p = .048), and this difference in pitching effectiveness evidently more than makes up for the fielding disadvantage of left-handed pitchers.
If we can assume that the balls hit to pitchers are (in a statistical sense) drawn from the same distribution whether the pitcher is right-handed or left-handed, then the fact that right-handed pitchers record more than twice as many 1-3 putouts per ball fielded must reflect a fielding superiority of right-handed pitchers. By far the most plausible explanation is the throwing mechanics explanation.
There are many left-handed pitchers in the major leagues because the fielding disadvantage of left-handed pitchers is not significant compared to the pitching ability of these pitchers.
An Aside on Counter-Clockwise Base Order
Have you ever wondered why in baseball runners run the bases counter-clockwise, instead of clockwise? That is, why first base is where it is, and not where third base is?
The answer almost certainly reflects the body mechanics described above, and the fact that approximately 90% of the population is right-handed. When the game was developing, it would have always been easier for most fielders, who were mostly right-handed, to throw across their bodies. Thus, first base is where it is, not where third base is.
There is an argument sometimes made that first is where it now is because it allowed right-handed batters to run “straight ahead.” But it would actually be faster for a right-handed batter to run to where third base now is. We know that because there is extensive data documenting that in today’s game, left-handed batters on average reach first base faster than right-handed batters, by about 1/10th of a second.[2]
If the direction of baserunning had been determined by batters, rather than by defensive considerations, it is possible that the bases would be run clockwise, because what is now third base is slightly closer to right-handed hitters.
First Basemen, Handed-ness, and Background Rates
Retrosheet data suggest that about 27% of all outs in major league games are recorded at first base. In the large majority (over 90 percent) of these outs, the first baseman is receiving a throw (from short, second, third and pitcher), catching a pop up, fielding a grounder and making the out unassisted, or fielding a grounder and making a short, low velocity toss to the pitcher covering.
Approximately 1.5% of all putouts[3] were scored 3-1 (meaning the first baseman to the pitcher) and virtually all of these were the first baseman fielding a grounder and making the toss to the pitcher. (This “routine play” was one of the plays that the Yankees failed to execute in the disastrous—for the Yankees—fifth inning of the fifth game in the 2024 World Series.)
The most common play in which the first baseman makes a throw to another base is the 3-4 play, in which the first baseman is throwing to second. This play represented 0.2% of all putouts recorded between 1952 and 2016.[4]
Shortstops, third basemen and second basemen throw to first 30 to 40 times more often than the first baseman throws to second.
Based on this analysis, we conclude that the first baseman throwing is such a minor aspect of defense that it is unlikely that the handedness of the first baseman makes a significant defensive difference.
Consistent with the hypothesis that handed-ness doesn’t matter for first basemen, we find that the frequency of left-handed first basemen in the major leagues does not differ significantly from the frequency of left-handedness among males in the general population.
About 10.5% of the general population of males is left-handed. (The rate of female left-handedness is slightly lower.[5]) In 2024, four of the 30 starting first basemen in the Major Leagues were left handers.
Four out of 30 equals 13.3%, and is consistent with BaseballAmerica.com’s report that left-handed throwers have made about 12% of the plate appearances in the majors over the last ten years.
Outfielders
Retrosheet data suggest that about 30% of all outs recorded in the majors are fly balls to the outfield. This estimate is higher than the estimate of about 26% derived by Chris Ford.[6]
But both estimates agree that the vast majority of outfielder-involved outs are caught fly balls, and not the result of outfielder throws.
Outfielder throwing is important, for example to limit runners’ advances on base hits to the outfield, and occasionally to throw out a runner seeking to advance on a sacrifice fly.
There is no evident reason relating to body mechanics or to field geometry to expect that the throws an outfielder makes are easier for right handers or for left handers. In other words, on average handedness should make no difference for outfielders.
And there is no evidence to suggest that handedness does matter.
Various estimates suggest that about 20% of all major league outfielders throw left-handed. That 20% prevalence is about twice the rate of left-handedness in the general population.
Does that two-times higher than the background rate suggest that there is something about left-handedness that makes left-handers better than right-handers at playing the outfield?
I believe the answer is no, and that we must look elsewhere for the explanation of the over-representation of left-handedness among outfielders.
That explanation, I believe, is simply that the outfield is almost the only non-pitching position open to left-handed throwers.
Grondin[7] and his co-authors found that about 13.5% of non-pitcher major leaguers are left-handed throwers. The expected proportion play first base, and the rest play the outfield, because they are unsuited to the other infield positions. And they don’t play catcher. We still haven’t answered why not.
So Many Left-Handed Pitchers
To answer the question why there are no left-handed catchers, we need to look at the tremendous over-representation of left-handed throwers among pitchers.
Though left-handers represent just 10.5% of the male population, left-handers threw 28% of the innings pitched in MLB between 2010 and 2019.[8] As authors Guy Molyneux and Phil Birnbaum state in the just-referenced article, “Left-handed pitching has long been one of the most prized commodities in professional baseball.”
Guy and Phil explain at length why lefties have such a big advantage as pitchers. They go so far as to state:
Indeed, our analysis suggests that a substantial majority of major league left-handed pitchers could not survive in the majors if they threw right-handed but had otherwise identical talent.
They argue, and support their argument with data, that left-handers on average throw less hard (1.5 mph difference), and their breaking balls have less break.
Nevertheless, they say, these deficiencies are overcome by a “familiarity effect.” They argue that through a batter’s career, he will face far more right-handed pitching than left-handed pitching. Therefore, batters are less familiar with the way the left-handed pitchers throw than they are with the way that right-handed pitchers throw and this gives left handers an advantage.
This familiarity effect is inferred from the observation that pitching outcomes are about the same between right-handed and left-handed pitches, despite the lefties’ stuff[9] being on average a little worse than righties’ stuff.
I argue that the fact that left-handed pitchers can be objectively less skilled than right-handed pitchers, combined with the scarcity of left-handed throwers in the general population, explains why there are no left-handed catchers.
Why No Left-Handed Catchers?
In short, there are no left-handed catchers because they are selected out early in their careers. Any left-hand throwing player with an arm good enough to be a catcher is moved, at some point early in his career, to pitcher.[10]
We have seen that there are approximately three times as many left-handed pitchers as would be expected based on the prevalence of left-handedness in the male population.
Where did all these extra left-handed pitchers come from? They must have come from throwers who had they been right-handed would not have been good enough to make the major leagues.
We have seen that among position players, who are selected almost entirely for their offensive capabilities subject to some minimum defensive capability, left-handers appear at about the prevalence of the general population.
Those extra left-handed throwers who could have been catchers, I hypothesize, instead become pitchers.
I was unable to find data to directly support the claim, but I believe it likely that in a player’s development, starting in Little League, any promising left-hander who can throw well will be tried out at pitcher. The chances are, if his arm is good enough to be a good catcher, he’ll be moved to pitcher.
There are a few attested instances of left handers moving from catcher to pitcher. Among them are Troy Percival, Kenley Jansen, Robert Stock, andChris Hatcher.
Relevance Outside of Baseball
I wrote this article primarily because I have long wondered about why there are no left-handed catchers. But in writing it, I was reminded that “the internet” while often wrong, seems never to be in doubt.
If you look for an answer to the left-handed catchers’ question on the internet, you are likely to find a list of reasons that don’t make a lot of sense. Google AI, for example, gave me these five reasons, none of which hold any water:
- Throwing Mechanics. The claim is that right handers have a mechanical advantage on throws to second and third. While it is true that right handers have an advantage on throws to third, the there is no such advantage on throws to second. But the proof that this claim is nonsense is that catchers make far more throws to first for putouts than to third. Chris Ford’s data show that .3% of all outs are recorded 2-3 (catcher to first). Thus, this “throwing mechanics” argument is actually an argument in favor of left-handed throwers behind the plate.
- Tagging runners out at the plate. Plays at the plate are rare, and whether the tagging motion would favor a right-handed or left-handed receiver is likely to depend on precisely where the throw arrived, which is probably a more important variable than the handedness of the catcher.
- “Positioning” which the Google AI bot explains means that left-handed catchers would have a harder time fielding bunts or other rollers on the third base side. This doesn’t even make sense.
- Right-handed dominance. This is a statement of statistics, but offers no reason for the complete absence of left-handed catchers.
- Tradition. But even assuming that is true, it is what we’re trying to explain!
If there’s a lesson here, it is the old lesson to be a careful consumer of information. Much of the critique of the internet focuses on the intentional spreading of “fake news” or propaganda, or claims seeking to advance some actor’s economic interest. I find it interesting, however, that even for something that virtually no one would consider political or commercial, that “the internet” gets it so wrong.
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[1] A statistically insignificant fraction of outs scored as 1-3 are successful pickoffs of a runner from first. Over the last 10 years, there have averaged about 320 successful pickoffs per season. This is less than ¼ of 1% of all outs, or said differently, fewer than 1 of every 400 outs.
[2] https://towardsdatascience.com/safe-the-effect-of-batting-hand-on-making-it-to-first-base-b89ac3a1888/
[3] https://web.archive.org/web/20160607200159/http://www.allmysportsteamssuck.com/2016/06/07/a-look-at-every-out-made-since-1952/
[4] Ibid.
[5] https://pubmed.ncbi.nlm.nih.gov/18729568/
[6] Ibid.
[7] https://ivrylab.berkeley.edu/files/organized_pubs_pdfs/1999_grondin_ivry_jephpp.pdf
[8] https://blogs.fangraphs.com/the-southpaw-advantage/
[9] “Stuff” refers to: “A pitcher’s assortment or repertoire of pitches collectively, together with his ability to deliver and control them in the proper sequence at the right velocity to the desired area of the strike zone”, per https://www.baseball-almanac.com/dictionary-term.php?term=stuff
[10] Catchers on average are the worst hitters among the position players. Thus, it is possible that if a young left-handed throwing player was too good a hitter to make into a pitcher, he would be moved away from catching because, everything else equal other positions are less deleterious to hitting. It could also be argued that catchers are worse hitters because of the abuse they take.
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