Overthinking It: Searching for Switch-Hitters Who Shouldn’t Switch-Hit

Every so often, someone asks me whether there are any switch-hitters who are making a mistake by batting from both sides, or whether a particular hitter would be better off picking and sticking to one side of the plate. There are two reasons, I think, why the question comes up even though there have been BP pieces about it before, and despite the fact very few players have ever stopped switch-hitting after making the majors.

The first is that switch-hitting is inherently interesting to those of us who can barely button a button with our non-dominant hand. Hitting baseballs thrown by big-league pitchers, we’re told, is one of the toughest tasks in sports. Switch-hitters can do it not only from the side of the plate where we look at least a little coordinated, but also from the side where we look like Hunter Pence. There are mutants in the X-Mansion with less impressive powers (like Longneck).

The second is that the subject feeds our need to find inefficiencies. We like to come up with ways in which a team or a player could add wins without paying what they’re worth. What could be more inefficient than a hitter who actively hurts himself by batting from his weaker side? And what could possibly cost less to correct? The idea’s allure makes us sound like those ads you sometimes see on sidebars: Hey, struggling switch-hitter—become a better batter by using this one weird trick!

So do these self-destructive switch-hitters we’re seeking actually exist? Probably, but finding and fixing them isn’t as easy as looking up the players with the largest platoon splits and telling them to hit from their stronger side.

For one thing, it takes time for platoon splits to stabilize. How much time? For switch-hitters, about 600 plate appearances vs. left-handed pitching, according to the authors of The Book. That’s about three full seasons, and even then you have to regress the observed split ratio 50 percent toward the league-average split ratio to get an accurate estimate of the switch-hitter’s true platoon talent.

For another, we can’t assume that if a switch-hitter were to stop switch-hitting, he’d immediately (or even eventually) have a league-average split from the left or right side. Some switch-hitters haven’t faced same-side pitching since PONY League, and all of them have thrived enough as switch-hitters to make it to the majors, which understandably makes them reluctant to stop. Both physically and mentally, it’s a difficult adjustment to make, and no team wants to pay for an adjustment period—not even if it starts during the offseason or spring training, since it’s so hard to say how long it might last.

To some degree, the duration depends on how a player learns. “Some guys are visual or experiential learners,” says BP’s resident psychologist/sabermetrician, Russell Carleton. “They learn by seeing and doing…and so in some sense, they are starting from scratch to build those pathways. Some guys are better able to abstract things and apply them in novel situations. The latter group would be better off than the former in trying to give up switch-hitting.”

But it might be that some switch-hitters would never adjust to facing pitchers from the same side, not enough to hit them as well as anyone else. While some switch-hitters started switch-hitting because they thought it would make them more attractive to teams, others did it because a physical limitation made them uncomfortable without a better look at the ball.

“I couldn’t pick up the curve from a right-hander without turning my head because of my problems with my left eye,” said Hall of Fame switch-hitter Red Schoendienst (who turned 91 on Sunday), explaining his decision to switch-hit. Schoendienst had injured his eye at the age of 16, when a nail ricocheted into it while he worked on a fence in the Civilian Conversation Corps. That kind of thing might be less common in the LASIK era than it was during the Great Depression, but surely some players are still switch-hitting despite their struggles from one side because they (or their teams) have reason to believe that they would do even worse without the platoon advantage.

Ideally, we would project a switch-hitter’s split as a lefty/righty only by checking to see how previous converts fared and applying the typical post-switch-hitting platoon split to today’s candidates. But we can’t, because the sample is not only selective but extremely small. Mariano Duncan did it and took a long time to adjust. J.T. Snow and Orlando Merced made the same decision but got up to speed quickly. After name-checking those three, we’ve just about exhausted our supply of previous players who made the majors, then made the change and maintained it over a span of several seasons.

So we can’t say with certainty that certain switch-hitters would be better off settling down with one side of the plate. But since you’ve made it this far, we’ll try to say it with some uncertainty.

First, we regress each switch-hitter’s observed platoon ratio, using the formula 600/(PA vs. LHP + 600) to determine the regression amount. Then we compare that to his estimated split as a non­-switch-hitter. But we also have to include a fudge factor to account for the fact that he’ll likely have a larger/worse split than the typical player. It’s impossible to say for sure what that fudge factor should be, but on the advice of Mitchel Lichtman, co-author of The Book, we went with one standard deviation in true talent.*

*If a switch-hitter were to hit exclusively from one side, he might be benched against the toughest same-handed pitchers, which would buoy his rate states. But it would also be a burden to his team, which would have to carry a caddy.

That one-SD adjustment, coupled with a minimum of 600 career PA vs. left-handed pitchers, leaves us with only a handful of good statistical candidates, one of whom just retired. (A few other players, like Wilson Betemit and Neil Walker, are just below the PA cutoff; Kendrys Morales clears the cutoff but would project to be just one point worse if he switched. You can see the whole, somewhat confusing spreadsheet containing all active switch-hitters here.)

Victorino made this list look good when a hamstring strain forced him to hit right-handed for some of last season, leading to a .300/.386/.510 line from that side with six homers. But we should probably pump the breaks on declaring the point proved: Victorino posted that line over only 115 regular-season plate appearances, and his BABIP vs. righties as a righty was over 30 points higher than his BABIP against southpaws from the same side. His strikeout-to-walk ratio was 25:3, his on-base percentage was pumped up by an incredible 11 HBP, and he slumped for most of October.*

*In an effort to snap out of that slump, Victorino tried facing Anibal Sanchez from the left side in Game Five of the ALCS. Afterwards, he said:

I thought I'd give it a try, but it wasn't what I expected. It just wasn't there. I saw the ball well, but I just wasn't comfortable with the swing and the whole approach. I felt as if I was trying to rush to get to everything. It's hard to change, especially since I hadn't done it for two months.

It had actually been closer to six weeks since Victorino’s last left-handed at-bat. If switching sides after six weeks causes that much discomfort, imagine trying to do it after years.

Victorino’s sample size aside, the estimated gains in that table aren’t insignificant. As a rule of thumb, an increase of one point of TAv translates to half a run over 500 plate appearances, which would put the benefit for Wieters at 5.5 runs—over half a win, at no cost to the Orioles. But keep this caveat in mind: the more obvious the stats say it is that a player should stop switch-hitting, the more likely it is that he has a good reason to stick to his seemingly counterproductive approach.

Before we finish, here’s a list of retired switch-hitters since 1950 who in retrospect seem like the best candidates to have hit from one side. A few things to keep in mind: first, left-handed hitters typically have larger platoon splits than righties; second, switch-hitting is much more common than it used to be, so it might make some sense that the iffiest switch-hitters would be concentrated in the past 30 years; third, the complete results are here.

Thanks to Rob McQuown and Mitchel Lichtman for research assistance.