Did you know? Catcher’s Interference. I DIDN’T!!!

Yours truly!  (not really, I'm way better looking!)

I wrote a short post on catcher’s interference (CI) some time ago, to educate people that reaching on CI does not impact your on base percentage (OBP).

Unfortunately, it has come to my attention (through an outstanding Sabermetrics course that I’m taking online) that in that post, my explanation of how to score it was… WRONG!  (sorry!)  No way to sugarcoat it, I’ve always been doing it incorreclty. I use my own spreadsheet system that takes the scoring from a game and compiles all individual
and team stats and I goofed on this one.*

It is true that Catcher’s Interference does not impact your on base percentage.  However, it DOES count as a plate appearance (PA). I always assumed that the formula for OBP was times on base (H+BB+HBP)  ÷ plate appearances.  So, if reaching on CI did not help nor hurt your OBP, then I assumed it did not count as a plate appearance.  Alas, it does.  The CORRECT formula for OBP is actually: (H+BB+HBP) ÷ (AB+BB+HBP+SF).  If a batter reaches on CI, it is counted as a PA, but the result of that appearance does not appear in any formula.

By the way, I still believe that intuitively it should be counted as a stat the same as a walk or hit by pitch. The counter argument is that you don’t know what would have happened without the CI. He may have been out anyways, so you don’t want to credit the batter for something he didn’t “earn”. But I think this counter argument can be used for HBP as well. Batters aren’t (usually) trying to earn getting on base by being beaned, but I digress.

* Note: Today there are several scoring apps available, so individuals don’t really need to know the rules that well, just mark it as a CI and the app will take care of calculating all the stats for you. Some of the best ones includes iScore as well as several others.