THE BOOK--Playing The Percentages In Baseball

Thursday, November 25, 2010

When a catcher can no longer catch…

This post is in the category of, “Just something I was thinking about the other day (or today)...”

Catchers are at the far right (the good end) of the defensive spectrum.  Just to the left is the SS, then the 2B (or CF), etc.  Catchers are typically the worst hitters (depending upon the era - there was a time when it was thought of as a power position), which makes sense, as offense is usually inversely proportional to where a player lies on that defensive spectrum.

Now, most players, as they age (or if they are deemed bad at their current position), at least at some point in their careers, move to the left on the spectrum. In fact, Bill James said a long time ago that players rarely move to the right, and he is correct.  Aging SS usually go to 3B or 2B.  Bad or aging 3B often go to the OF or 1B.  Outfielders move to first base or DH.  Etc.

But what about catchers?  They certainly don’t go to SS.  I can’t think of any catcher who ever went to CF, which is 3 spaces to the left.  They rarely even go to the corner outfield spots because they are usually not fast enough, especially an older catcher (whose legs are likely shot).  They sometimes but not often go to 3B (Inge, Torre) or 2B (Biggio).  They often, at least as far as I can recall off the top of my head, go to first base and DH (think Victor Martinez, Piazza, Posada), or at least they often switch back and forth from catcher to these positions.

What does that mean?  It means that catchers, when they switch positions as they age, unlike most other players who might move one or two spaces to the left, lose a tremendous amount of value - often all of their above replacement value. I would assume that because of that almost all the catchers who do move to first or DH are very good or great hitters.  The rest retire or become back-up catchers.

What does that mean?

If you are a catcher and are not a great hitter, you better make sure you can catch for a very long time or you will be out of baseball in a heart beat.

In more sabermetric terms it means that catchers really are the “odd man out” in that defensive spectrum (which we sort of knew already) and it means that their aging curves, once you include positional adjustments, are very different from other positions - much steeper after the peak.  Imagine constructing an aging curve for a typical non-catcher.  Their offensive declines after age 27 or so and so does their defense, whether they switch positions and you do a positional adjustment or not.  Now imagine that aging curve for a catcher.  Their offense (and base running) declines, perhaps more so than for other positions because of the rigors of catching, AND at some point, you have to assume that their positional adjustment goes from +12.5 runs (catcher) to -12.5 (first baseman) or -17.5 (DH). Wow!  What is THAT aging curve going to look like?

Again, just something to think about…