Questions About BABIP and "xBABIP"

[Spy Fox]

Ever since I heard of BABIP, I thought it seemed an oversimplification-- in my mind it was obvious that high or low BABIPs were going to be affected by simply being a better or worse hitter just as often as they were going to be affected by good or bad luck.

You can make guesses about how lucky a player's BABIP is by looking at line drive and ground ball rates but it's not very scientific. Just today I came across an article describing a variation I had never heard of, xBABIP (similar I guess to xFIP), which used equations incorporating a few factors (especially batted ball rates and speed) to determine what the expected BABIP of a player would be.

Does anyone know anything else about xBABIP? Seems like a very useful tool, a good companion to BABIP to better determine which players are actually lucky or unlucky, but I have never seen it used before. Is there no consensus method on how to calculate it? Is it something that is very popular in advanced stats but hasn't become widely used? I didn't see it on the standard stats page at fangraphs or baseballreference, are there any websites that track it?

[TakebackOPACY]

Okay. xBABIP just means Expected BABIP (Spy Fox, I know you already figured that out, but I figured I'd spell it out for others). It's a really interesting tool that is still being refined. If one wants to take their fantasy geekdom to the next level before draft day, it's right up one's alley.

A few things we think we know without waiting for xBABIP to calculate it for us... a slow guy is going to have a lower BABIP because he gets thrown out at first more often. When a guy has the extreme shift put on him because he can't go to opposite field, his opponent is basically saying they can decrease his BABIP because of his lack of ability to go with the pitch. A fast lefty who can put the ball wherever he wants it and is also a skilled bunter will have a high BABIP. There are more factors but you get the point.

So my gut feeling is that xBABIP is underutilized because it's not very often that it surprises us and tells us something we didn't kind of already know. For most purposes, the detail that xBABIP gives us beyond what we already knew comes with a grain of salt because of the amount of fluctuation from the end results anyway.

[birrman54]

I'd also say that while BABIP can be used to help determine whether a struggling player is under-performing - it was meant to be used to analyze pitchers.

Since pitchers are facing a variety of hitters of varying skills - they're BABIP is less controllable than an individual batter.

This fangraphs forum thread may be helpful http://www.fangraphs.com/forums/topic.php?id=3680

[RVAbird]

I'd also say that while BABIP can be used to help determine whether a struggling player is under-performing - it was meant to be used to analyze pitchers.

Since pitchers are facing a variety of hitters of varying skills - they're BABIP is less controllable than an individual batter.

This fangraphs forum thread may be helpful http://www.fangraphs.com/forums/topic.php?id=3680

Right.

The blanket statement that BABIP tends to regress toward the mean has always been intended to describe trends for pitchers. The reason is simple - the "skill" of BABIP lies more squarely in the hands of the hitter than the pitcher.

Of course, randomness creeps into BABIP for everyone, as chance and circumstance have toes in every baseball pond. But, so much as BABIP can be controlled, it is controlled moreso by hitters - dictated by bat speed, swing plane and a host of other factors over which pitchers exert no control.

I would say that 90 percent of BABIP analyses I see on hitters are malapropisms.

[Spy Fox]

Thanks to everyone for the information.

I had never heard that BABIP was originally intended more as a pitching metric, and it makes sense that luck would influence the pitching side more than the hitting side of this.

It also makes sense that in most cases, especially over long sample sizes, the xBABIP won't significantly differ from the BABIP very often for hitters.

[RVAbird]

Christina Kahrl aptly weighs in on BABIP for hitters in ESPN's Sweet Spot blog. Very apropos to the discussion in this thread.

http://espn.go.com/blog/sweetspot/post/_/id/11259/chone-figgins-obp-and-babip