BIP Question

[kvnm77]

This may have already been covered, but I couldn't find it in a search (and there's an excellent chance I'm simply missing something so I'm hoping somebody can explain it to me):

I've seen two different Balls in Play calculations for pitchers. One on the website here: http://www.baseballhq.com/glossary-b which shows it as In the 2015 Forecaster (and 2014/2013 as well) it's listed as (Batters faced - (BB + HBP + SAC)) + H - K.

The question I have is about the Hits stat being included in the book formula. It makes sense to me to include it in the website formula as that is being calculated from a pitcher's IP which does not account for Hits he has given up, only outs. However in the book formula, it is calculated from batters faced, which should already include hits.

For an example, take a pitcher who's stat line is 2 IP, 1 H, 1 BB, 2 K, (and 4 outs in play, no double plays so 8 total batters faced).

Here, the BIP should be 5 (the 4 outs in play plus the hit).

Using the web formula ((2 x 2.82)) + 1 - 2 = 4.64 BIP (approximate based on IP, rounded = 5)

Using the book formula (8 - (1 + 0 + 0)) + 1 - 2 = 6 BIP

It seems to me that for calculating balls in play using batters faced, all outcomes are already included. So it is necessary to take out balls not put in play (the Ks and BB here) - but not the hits.

So I would think this makes more sense (Batters faced - (BB + HBP + SAC + K)), and in the example above would yield (8 - (1 + 0 + 0 + 2)) = 5.


Now, I completely understand I may be off my rocker here and like somebody who looks as something too long, I'm missing something simple - so feel free to slap me on the head if necessary...

[RAY@HQ]

The glossary formula, with the 2.82 component, was used as an approximation when we didn't have actual batters faced data (the 2.82 represented the 3 outs, minus outs that don't come on BIP or K... CS, DPs, pickoffs, etc). But I need to update that, as (I believe) we have actual batters faced data everywhere on the site now. (We still use the 2.82 for projected stats, since we don't project some of those CS/DP/pickoff elements).

As for the question about the formula in the book... I believe you're right: hits would be included in the Batters Faced count.

The other consideration you're omitting is that technically a HR isn't a ball in play, so you would want to take those out too. So:

Balls in Play = (batters faced - (BB+HBP+SAC+K+HR) )

I'm 99% sure we have this coded on the site the right way, and just wrote it wrong in the book glossary. But I'll confirm that.

Thanks for the post. Not off your rocker at all.