Articles about lefty catchers will stop making the rounds for one of two reasons: lefties are accepted at the professional level as viable contributors at the position, or sufficient evidence confirms they are at an inherent disadvantage to right-handed throwers. As it stands now, the traditional arguments against it happening are unsubstantiated at best, and just plain stupid at worst. Here I collect some of the most common arguments against the cause, as well as the best reasons why these arguments are unfounded, and why this is an untapped source of value for every major league team.
First up is the issue with tag plays at home plate. Since lefty throwers catch with the right hand, they have to position themselves differently to make a swift tag on the runner. Some worry that this leaves them susceptible to more home plate collisions. But wait! Collisions at home are soon to be a thing of the past, allowing catchers to tag runners with a bit more confidence than they used to. Runners will have to avoid contact on scoring plays, just like every other base. A left-handed player at home plate can set up much in the same way a right-handed fielder catches a pickoff throw at first base. He can either tag across his body, like Joe Mauer here:
Or he can turn his back to the runner and make a blind swipe tag like Chris Davis here, without worrying about getting run over:
Catchers must make throws to every base on stolen bases, pickoffs, balls they’ve blocked in the dirt, and bunts in front of home plate. For throws to second base on steal attempts, many traditionalists posit that left-handers have a disadvantage throwing since their ball tails away from the runner. To me, this is the most enraging argument on the topic. We are talking about some of the premier athletes in the world, masters of their sport, and assuming they won’t pick up on the fact that their throws tail. Either learn how to throw straight or aim further to the right. That’s dumb.
Others argue that it takes longer to get the ball to second when a hitter is standing in the way. Most batters are right-handed, standing on the side of the catcher’s left arm. But if this were important, we should see a distinct difference in stolen base success when left-handed batters are up to bat. Surely right-handed throwers would have the same problem then. In a 2009 article for Baseball Prospectus, Tim Kniker compiled league-wide stolen base percentages over a five-year span with righty and lefty batters at the plate. He found no statistically significant difference — the stolen base success rates were 79 percent while lefties were at bat and 78.5 percent with right-handed batters. We can poopoo this one.
Not only does this logic not hold up, there is pretty strong evidence that catchers do not have as heavy an influence over the running game as you would expect. Max Weinstein has done some great work over multiple articles, most notably here and here, attempting to quantify how much blame can be placed on the catcher for a stolen base. He uses two methods to answer the question: historical caught-stealing percentage for the pitcher and catcher, and pitcher times to the plate and catcher pop times on specific stolen base attempts. In both, the numbers show the pitcher is about twice as influential over the likelihood of retiring the runner, and by extension is twice as responsible for controlling runners on first base.
On to third base, where lefties may actually have a disadvantage. When a runner is stealing third, a left-handed thrower has to switch his feet to make a throw across his body, likely allowing the runner an extra step. However, talk to anyone in the game about stealing third base, and you’ll hear it is almost always on the pitcher if a runner successfully advances. While the pitcher is statistically twice as responsible for steal attempts to second, that number certainly climbs way up for third base. Runners do not take advantage of pitchers who are slow to the plate in this situation; rather, they pay attention to when pitchers fall into habits with set times and number of looks to get an extra jump.
If there is an advantage for throwing runners out, it should show up in the game pop times, with right-handed catchers being noticeably faster to third base than first base. I looked at pickoff throws and stolen base throws to first and third, respectively, from 2013 for the top nine qualifying catchers according to The Fielding Bible‘s rSB stat. (I used the top nine because that was everyone who was at average or above in the metric.) For this group, I found 30 plays in the video archives where a runner was thrown out at third or first. I got rid of 10 of these plays because they were not useful for measuring glove-to-glove pop time, due to some form of delay between catch and throw. Here are the composite data for the observed pop times, for eight pickoffs at first base and 12 caught stealing throws to third:
|Catcher Pop Times to First and Third|
|Breakdown||First Base||Third Base|
A difference of only .040 seconds between the two groups, though there is certainly a wider spread on the numbers for third base. For the six catchers for whom I had timed throws to both first and third base, the average difference was only .032 seconds. Just for fun, here are the fastest throws to first and third by Salvador Perez and Matt Wieters.
Salvador Perez pickoff to first – 1.40 seconds
Matt Wieters throw to third to nab stealing runner – 1.27 seconds
While it certainly seems catchers can be quicker to third base than first, the actual difference come game time is not as appreciable as expected. If I am interested in reducing the number of runs scored against my team, I would lean toward holding runners close to first rather than worrying about steals of third.
The risk a team takes by attempting to steal third is much higher than second base on average, as evidenced by the higher break-even success rates shown in the graphs here. The payoff is not as high stealing third base most of the time. The average run value of an extra base is worth about .25 runs according to The Book, though that number varies depending on who you talk to and what period you look at. I would guess that this value is a bit higher today as power continues to decline across the league. The average successful stolen base is worth .2 runs.
With a left-handed catcher behind the plate, runners would be forced to stay closer to the first base bag on their secondary leads, making it more difficult to take two bases on a single or score on a double. Hypothetically, let’s assume one out of 10 steals of third is the responsibility of the catcher. If a catcher can keep just one runner from taking an extra base in the same amount of time it takes for 10 guys to attempt to steal third, he has more than made up for the disadvantage. Runners are on first base far more often than they are on second, so the number of chances to impact the running game is much higher at first than second.
Lefties also have an obvious advantage fielding bunts and making throws to first, particularly down the third base line. Righties are forced to take more steps or throw off balance for a well-placed bunt on the left side. Having a left-handed catcher would allow the third baseman to play another step back, potentially taking away an extra hit or two.
In terms of receiving, I originally thought lefties would have a huge advantage over righties, since they could expand the zone against right-handed batters, which are still the majority at this point. Right-handed catchers enjoy an expanded strike zone on the outside corner when lefty batters are up. Umpires set up on the inside corner to protect themselves from most foul balls. Catchers can receive the ball on their glove side without having to move as much of their bodies, making more pitches appear like strikes there when the umpire is on their arm side. However, data show that the strike zone does not get bigger, but rather just shifts over a few inches, presumably because reaching across the body to the arm side makes some inside strikes appear like balls to the umpire.
Jon Roegele researched how the strike zone changes in myriad conditions, showing that in 2012, the strike zone to right-handed hitters was actually seven square inches bigger than that for lefties (460 to 453). Here are some lovely images of the 2013 strike zone from Baseball Heat Maps:
2013 Right-Handed Hitter Strike Zone
2013 Left-Handed Hitter Strike Zone
We can probably assume a left-handed catcher would have the same shift with right-handed batters up. There may be some advantage to the strike zone being different with a lefty receiver behind the plate, but surely major league hitters would be able to adjust to a shift more than an expansion of the zone. As an aside, I think it would be interesting for a catcher of either persuasion to use a switch-mitt, like what switch-pitcher Pat Venditte uses.
I even asked a glove company to make one out of curiosity; I never got a return call. Hypothetically, catching with either hand (with no threat of a steal obviously) would allow a catcher to take advantage of both corners expanding. Aside over.
It is important to mention that this potential advantage may not be as useful if the current trends continue, however. A more recent article by Roegele for The Hardball Times illustrates how the outside border of the strike zone has been slowly moving back over the plate, particularly for left-handed batters. As you can see in heat maps above, the difference is still obvious; it is just less so than it was a few years ago.
The last reason I believe lefties should be allowed to catch is the advantage they would have as hitters. We know that left-handed hitters have the platoon advantage more often than right-handers do. What may not be as obvious is that left-handed throwers have a more natural hand path in their left-handed swings than left-right combos do. When catchers are excused in from working on their swings due to their defensive obligations, why not put someone in that position who can more comfortably swing like he throws. This is a much more debatable topic, especially since survivor bias at the major league level makes it nearly impossible to show statistically. In my experience, it is much more difficult to get hitters to understand the proper swing if they do not have a natural throwing motion with their top hands. It’s the same arm action whether throwing sidearm:
The hands load up under the back elbow, followed by the elbow and hand(s) switching places as the elbow drops under the shoulder. This move with the elbow creates the first segment of the whip as the ball or bat is propelled forward. It allows energy to be created without having to use large, slow muscle groups to do it. In hitting, the elbow attack allows the hands to stay inside the baseball and extend all the way through the ball after contact.
Players do not have to be life-long catchers to play there in the big leagues. Russell Martin and Jorge Posada were two of the most notable catcher conversion stories of the past 20 years; both started as infielders and converted after being drafted. Buster Posey converted in the middle of his college career after never playing the position at any level before then. You don’t have to look hard to find left-handed first basemen and outfielders in minor league baseball who could raise their stock by changing positions.
I can think of at least one potential candidate in every organization that I have scouted in my spare time. As a left-handed position player, your options are already limited if you don’t have plus speed or power. Surely there are some athletic players with soft enough hands that could approximate an average catcher, but wash out of pro ball because they do not fit the traditional positional profile of a left-handed thrower. It certainly would not hurt the average offensive production from the catching position to increase the available pool of players.