As we all know, catcher defense is difficult to quantify and probably even more difficult to predict. Nevertheless, one of a catcher’s most important jobs behind the plate is to prevent base runners from swiping bases. Dan Turkenkopf’s article over at Beyond the Boxscore about a month ago projected catchers’ block percentages for the upcoming season and it gave me the idea of attempting to project catchers’ ability to prevent runs by preventing the stolen base.
For this experiment, I used essentially the same methodology used by Turkenkopf in his article, specifically the Marcel based 5-4-3 approach to projecting runs prevented for the 2010 season. This means that I used catcher data from the last three seasons to project caught stealing percentage as well as the number of stolen base attempts against each catcher if they all played 120 games (1080 innings) behind the plate. For the run values, I used those identified in The Book — plus 0.467 runs per caught stealing and minus 0.175 runs per stolen base. Then I determined the average number of runs prevented by the catchers over those 1080 innings and figured each catcher’s runs above or below average. For those catchers with less than three full years in the league, I used minor league caught stealing percentages and major league attempts against over a 120 game period.
The table below shows the results. (For purposes of conciseness, I’m only including primary backstops. The full google spreadsheet may be found here.) ProjSBA is projected stolen base attempts. ProjCS% is projected caught stealing percentage. SBRAA and CSRAA are stolen base and caught stealing runs above average, respectively, based on their respective run values. 2010RAA is simply CSRAA minus SBRAA and 2010RAA is 2010RAA/120 based on 120 games of work.
|**Yadier Molina would be much further ahead of the pack if runners dared to run against him more frequently.** (Icon/SMI)|
First of all, this is based on historical catcher data over the previous 3 years and pays no attention to new pitchers on the catchers’ respective teams and their ability to hold runners on. Second, Yadier Molina — the best defensive backstop in the game — would be much further ahead of the pack if teams were willing to run against him. The fact that many catchers have twice as many stolen base attempts against tells us that teams realize that running against Yadi is a risky proposition. Third, I was surprised at how high Wieters and Mauer finished on this list. The primary reason, beside the fact that they are respectable at throwing runners out, is that they may be better than their reputation. That is, by risking running against them, teams make them better. Ryan Doumit and Kurt Suzuki are projected to be roughly league average catchers at throwing out base runners. The difference between the best and worst in the game is just more than one win per year.