Question on batters h%

[Phanatic]

Can someone either point me to the right place to learn about batters h% or explain it here?

I have looked in the Glossary as well as in the forecaster's toolbox, but the only thing I can find is h% for pitchers -- Voros McCracken's theory.

Trying to better understand this particular BPI.

Thank you.

[PD@HQ]

I'm not sure where it is with the redesign of the site, but I did a lot fo the original work on Hitters' H%--what kind of info do you need? In a nutshell, what I learned was that hitters, unlike pitchers, tend to establish individual H%s that are quite stable over rolling three-year periods, and that an unexplained swing away from that established level in year X is a decent predictor of a regression in year X+1. Note that the regression is not predictable or prjectable within a single year because of small sample sizes.

[Phanatic]

Thanks...just trying to better understand the concept...was looking for a definition, but I'm pretty sure I get it now.

So you're saying that generally hitters will come back to the rolling 3-year H% with the exception of that year X+1?

[Tom_T]

FYI, the formula is:

(H - HR) / (AB - HR - K)

[RAY@HQ]

That's essentially correct, phanatic. Once a batter "establishes" a hit rate over a couple of years in the majors, he'll tend to revert to that. Note that the research was only in full-season samples, we haven't looked at it as an in-season predictive tool.

In other words, if a guy has hit rates of 31%, 32%, 33% over 3 years, then hangs up a 26% in Year 4, you'd still expect to see a ~32% in Year 5. But the same does not hold true (that we can prove) if he goes 31-32-33 in April-May-June then 26% in July... that doesn't mean we know what will happen in August.

As far as where to find the initial research, I believe Patrick Davitt wrote the piece for the 2004 Forecaster. I'm not sure that article has ever been available on the site. But if you've got the 04 book, it's in there.

[PD@HQ]

Slight correction... Ray says we haven't looked at H% as in-season predictor, but I did and it doesn't work.

[Phanatic]

Thanks guys. This is EXACTLY what I was looking for!

I appreciate your assistance.