CSS Button No Image Css3Menu.com

Baseball Prospectus home
Click here to log in Click here for forgotten password Click here to subscribe

<< Previous Article
Premium Article Minor League Update: S... (02/27)
<< Previous Column
Premium Article Skewed Left: Fun with ... (02/13)
Next Column >>
Premium Article Skewed Left: The Art o... (03/06)
Next Article >>
Premium Article Overthinking It: Why E... (02/27)

February 27, 2014

Skewed Left

What it Means to Move Off Catcher

by Zachary Levine

the archives are now free.

All Baseball Prospectus Premium and Fantasy articles more than a year old are now free as a thank you to the entire Internet for making our work possible.

Not a subscriber? Get exclusive content like this delivered hot to your inbox every weekday. Click here for more information on Baseball Prospectus subscriptions or use the buttons to the right to subscribe and get instant access to the best baseball content on the web.

Subscribe for $4.95 per month
Recurring subscription - cancel anytime.

a 33% savings over the monthly price!

Purchase a $39.95 gift subscription
a 33% savings over the monthly price!

Already a subscriber? Click here and use the blue login bar to log in.

One of the favorite storylines this time of year is the positional change, whether it’s putting on an entirely different kind of glove or just moving over a few dozen feet to the left or right. Predicting performance changes is hard, but a positional change is something we can see, so it’s something we can write.

One of the least-favorite storylines—or at least most confusing—is when a positional change comes with a promise that the player will be able to improve on offense because he can spend more time working on it.

You’d think this would be particularly true with catchers. Shortstops, for instance, spend as much time taking ground balls as their counterparts down the defensive spectrum at second and third do. But if this were ever going to be true, you’d think it would be with catchers. Every day before the game, while the other position players are taking extra hacks in the cage—which may or may not help, granted—the catchers are sitting in with that day’s starting pitcher and the pitching coach going over the opposing lineup.

This winter, we learned that a couple of long-rumored moves were going to finally happen. In the much longer-rumored instance, Joe Mauer isn’t listed in the top four of the Twins’ official site’s depth chart behind the plate. He’ll be the starting first baseman and will presumably DH from time to time as well. Then there’s Carlos Santana, whom the Indians will move to third base with Yan Gomes taking the majority of the crouching.

Baseball doesn’t provide a ton of history of such moves to analyze whether they have any immediate impact on offense, and beyond that, the confounding variables present a problem. A move from behind the plate can come not for prevention, longevity, or defensive purposes, but as a direct result of an injury that we’d expect to see the player bounce back from on offense as well. So in looking at the predecessors of Mauer and Santana, neither of whom has been without injury concerns, we limited it to those with at least 70 games behind the plate the year immediately before the move.

As a result, there’s really not a lot of history to look at. In fact, there was a 14-year period leading into the WARP era in which nobody fit the category. But since 1958, there have been 68 qualified players who played the majority of their games at catcher and switched the next year to play the majority at another position (not pinch-hitter or pinch-runner).

Where did they go? Mostly where Mauer is headed. A few to the other corner or DH. A few to the corner outfield spots, and of course one future Hall of Famer to second base.



To 1B




To 3B






To 2B


So all of them moved to positions where more offense would be expected, but of course they were still the same players. Now, you may have thought that their offense would improve as a result of having the hardship lifted, as I did, or you may have thought they’d decline because hey, these are often old guys who can’t handle catching anymore, and that’s what old people do—they decline. Either way, you would have been wrong. Offensively, on average, they stayed exactly the same.

A .266 true average before. A .266 true average after.

And they stayed pretty true to their aging curves as well. Offense for catchers has tended over the last five decades to peak at 28.* As players aged closer to that peak, their TAv tended to go up, in line with what we’d expect. As they aged past it, their true averages went down, as you might expect from an aging player. So that’s some explanation for why with younger players, the drop in positional value was somewhat masked, whereas in the 29-and-older set, a move off catcher has tended to be synonymous with a plunge in value.

*Actually, the highest TAv for catchers is at age 42, and there are other local maxima at 21 and 40, but there’s some extreme survivor bias (the 42s) and selection bias (the 21s) there.

The full breakdown is as follows. (One thing to note: Average playing time was almost identical before and after moves off catcher, so the positional adjustment is largely responsible for the decline in value.)

Age (after move)

TAv before

TAv after

Avg. WARP before

Avg. WARP after

Up to 28





29 and older





All players





What was most surprising, though, were the numbers in each group. Moving off catcher has not historically been reserved for the oldest players. The median age to move is between the age-28 season and the age-29 season, and this doesn’t even count the Wil Myers or even Bryce Harper types who just gave up on catching before getting to the majors. The modal age is a year younger.

For every Mike Piazza, who despite never being a great defensive catcher (by traditional metrics, if not more advanced ones) didn’t vacate the position until age 38, there is a Biggio, who was moved off it quickly. For every Jorge Posada, who was the oldest player on the list ever to move off catcher, going to DH at 39, there is a Todd Zeile, who didn’t last past his age-24 season at the position. Zeile was sixth in rookie of the year voting as a catcher in 1990 and then never played it again for a single game until he was a 38-year-old Met in 2004 – his second go-around with one of his 11 teams.

With true average normalized around .260, the move off catcher is not only done with young players, but it’s done with young players who play a lot with below-average offense, moving them to positions where more offense is required. And that feels like the most surprising part. The young players aren’t even the Myerses and Harpers. They’re not even the Santanas (the Santana in question had a TAv of .305 last year). And if they respond, it’s often just the natural progression of the aging curve.

At least for catchers, there seems to be very little to a player’s ability to improve just by concentrating on the bat.

Zachary Levine is an author of Baseball Prospectus. 
Click here to see Zachary's other articles. You can contact Zachary by clicking here

13 comments have been left for this article. (Click to hide comments)

BP Comment Quick Links

Brock Dahlke

The argument i've most heard is that offense should go up because of not dealing with foul tips and such, not "concentrating on hitting more".

Feb 27, 2014 07:24 AM
rating: 0
Other readers have rated this comment below the viewing threshold. Click here to view anyway.

In my upcoming draft is there a scenario where u take alfaro over Jonathan Gray??

Feb 27, 2014 10:31 AM
rating: -13

Sticking with the topic of the article. I like it.

Notice how this guy has posted the same question in multiple articles today.

Feb 28, 2014 10:43 AM
rating: 1
Dave Scott

First guy I thought of was Joe Torre, who went from C to 3B and won a batting title.

Offense for catchers tRends has tended
and maybe even


But overall, I'm impressed with BP's editing.

Feb 27, 2014 10:38 AM
rating: -1
BP staff member Ben Lindbergh
BP staff


Feb 27, 2014 13:29 PM

Dale Murphy moved from catcher to center field for the Braves. Didn't see any center fielders listed.

Feb 27, 2014 13:52 PM
rating: 0

He was never a half-time catcher over a full season. He high for games caught was 27. Spent most of 1978 and 1979 at first.

Feb 27, 2014 15:56 PM
rating: 1

Okay they're not hitting any better, but they'd have to be in the lineup more, and consequently able to contribute to the offense more often.

Feb 27, 2014 15:35 PM
rating: 0
BP staff member Ben Lindbergh
BP staff

Zachary noted that "Average playing time was almost identical before and after moves off catcher."

Feb 27, 2014 15:56 PM

Oh my bad.

Feb 27, 2014 16:07 PM
rating: 0
Peter Benedict

I don't remember... is TAv positionally adjusted? If so, that's a huge offensive improvement for players moving to 1B, no?

Feb 27, 2014 19:06 PM
rating: 0
BP staff member Ben Lindbergh
BP staff

It's independent of position.

Feb 28, 2014 10:45 AM

Good inquiry here, Zachary. I have a recent paper that suggests catchers get more favorable calls from the umpire (for whatever reason), and perhaps some evidence that it is less favorable when they aren't behind the plate.

I didn't have enough data to go very far on the front of how that actually affects performance (or whether the effect I saw was persistent once one leaves catching), but it might lead to one suggestion about what might be happening.

We like to think that performance increases because of *insert reason here*. Maybe the overall bat does. But, on the other side, perhaps the less favorable umpire calls ultimately make it a wash (but perhaps make careers longer, and allow solid performance at the plate for a longer period).

In any case, I have no idea if this is happening, but it's just another piece of evidence I found interesting. Thanks for sharing!

Feb 28, 2014 12:53 PM
rating: 0
You must be a Premium subscriber to post a comment.
Not a subscriber? Sign up today!
<< Previous Article
Premium Article Minor League Update: S... (02/27)
<< Previous Column
Premium Article Skewed Left: Fun with ... (02/13)
Next Column >>
Premium Article Skewed Left: The Art o... (03/06)
Next Article >>
Premium Article Overthinking It: Why E... (02/27)

West Coast By Us: Yo
Premium Article The Prospectus Hit List: Friday, May 29
Premium Article Minor League Update: Games of Thursday, May ...
Premium Article Rubbing Mud: Context is King
Premium Article Daisy Cutter: How the Kipnis Got His TAv
Premium Article What You Need to Know: Another Day, Another ...
Premium Article Release Points: Where Have You Gone, Stephen...

Premium Article Minor League Update: Spring Training Games o...
Premium Article Rumor Roundup: An Infield Fix for the Yankee...
Fantasy Article Dynasty League Positional Rankings: Top 175 ...
Fantasy Article Fantasy Three-Year Projections: Starting Pit...
Fantasy Article Fantasy Freestyle: The Rising Cost of Pitchi...
Fantasy Article Tale of the Tape: Matt Cain vs. Zack Greinke
The BP Wayback Machine: Carl Pavano: A Caree...

2014-03-13 - Premium Article Skewed Left: The Good and the Bad News About...
2014-03-07 - BP Unfiltered: Your Attempts To Explain Base...
2014-03-06 - Premium Article Skewed Left: The Art of Explaining Baseball
2014-02-27 - Premium Article Skewed Left: What it Means to Move Off Catch...
2014-02-26 - BP Unfiltered: Sabermetrics Goes MOOC
2014-02-13 - Point/Counterpoint
2014-02-13 - Premium Article Skewed Left: Fun with 2014 PECOTA Comparable...

2014-03-20 - Premium Article Skewed Left: Where Are All the Australian Po...
2014-03-13 - Premium Article Skewed Left: The Good and the Bad News About...
2014-03-06 - Premium Article Skewed Left: The Art of Explaining Baseball
2014-02-27 - Premium Article Skewed Left: What it Means to Move Off Catch...
2014-02-13 - Premium Article Skewed Left: Fun with 2014 PECOTA Comparable...
2014-02-06 - Premium Article Skewed Left: The Truth About One-Day Contrac...
2014-01-30 - Premium Article Skewed Left: Saying Goodbye to Lance Berkman

2014-03-26 - Premium Article Prospectus Preview: AL Central 2014 Preseaso...