The Rays Rotation and BABIP

by R.J. Anderson on Jan 14, 2010 11:36 AM EST

James Shields' BABIP and inning totals over each of the last four seasons:

2006: .332 (124.2)

2007: .292 (215)

2008: .292 (215, not a misprint)

2009: .317 (219.2)

League average BABIP against is generally between .300-.305. That means that Shields' BABIP has split between ‘above average' in disallowing hits and well below average. So what should we expect moving forward? Russell Carlton found that at 1,500 balls in play, the R value reached .50. Using the equation R = BIP/(BIP+1500) we get this equation for Shields:

R =2365/(2365+1500)

R =2365/3865

R =0.612

Essentially, that means to get a read on Shields' BABIP true talent BABIP level, we need to regress his career BABIP by nearly 39% with the team's BABIP against. Over the last three years the Rays' BABIP against is .299, .285, and .338 which weighs to a .304 BABIP. Frankly, I'm not too sold on using the 2007 figure because that's simply not representative of what to expect from this team defensively. Sub in a league average season instead and the figure drops from .304 to .296. I'll use the .296 in regression, although I can provide the .304 numbers if anyone wants them.

Upon doing that math, you'll find that his career BABIP (.306) is identical to the regressed rate (.306, rounded, mine you). Using that same technique, here are the regressed rates for the remainder of the Rays rotation:

Pitcher	cBABIP	BIP	rBABIP	Net
Shields	0.306	2365	0.306	0
Garza	0.299	1574	0.298	-0.001
Sonny	0.323	1415	0.309	-0.014
Niemann	0.306	614	0.299	-0.007
Price	0.277	428	0.292	0.015
Davis	0.318	100	0.297	-0.021

All of this to say: Wade Davis only had 100 balls in play against. Don't worry about his hit rate. That's a ridiculous small sample size; one that had to be regressed by more than 93%. At the same time, don't expect Price to continue at such a ridiculous pace of not allowing hits. Sonnanstine may look hittable or whatever, but in reality his expected BABIP is close to Shields -- the Rays best starter. (It's also worth noting that Sonnanstine's BABIP is close to Shane Reynolds through 400 Major League innings, and lower than Brad Lidge's, who has superior stuff in a reliever's role).

Keep sample sizes and the granularity of data in mind before jumping to conclusions. Yeah, this is close to common sense, but sometimes it needs to be written and showing the math helps with the stigmatism surrounding regression.

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Comments

What does the 'r' and 'c' stand for?

I’m assuming ‘r’ is regressed; is ‘c’ career?

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by BWoodrum on Jan 14, 2010 11:43 AM EST reply actions

Yessir.

by R.J. Anderson on Jan 14, 2010 11:43 AM EST up reply actions

It would be nice if you put the actual years

next to the first set of four numbers that you present.

by RaysTheRoof on Jan 14, 2010 11:47 AM EST reply actions

Fixed.

by R.J. Anderson on Jan 14, 2010 11:49 AM EST up reply actions

So would we be better off with a Twins-type philosophy of looking for strike throwers that don't walk anyone?

Paying for K’s can be expensive, if there is a proven advantage in turning BIP into outs, it would seem we could benefit from low-walk pitchers more than high-strikeout pitchers.

I'm a writer.

by Andy Hellicksonstine on Jan 14, 2010 12:13 PM EST reply actions

I'd rather not be known as the organization that produces Carlos Silvas.

by R.J. Anderson on Jan 14, 2010 12:28 PM EST up reply actions

Oh god, my Cubs heart is melting. :(

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by BWoodrum on Jan 14, 2010 12:31 PM EST up reply actions

Just wait until you sign Nick Blackburn for 4/$48M

by R.J. Anderson on Jan 14, 2010 12:32 PM EST up reply actions

You're giving me an ulcer.

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by BWoodrum on Jan 14, 2010 12:58 PM EST up reply actions

I'm not saying Livan Hernandez or Carlos Silva, but if given the choice of a high K/high BB/low contact pitcher (Jorge De La Rosa)

or a Low K/Low BB/High contact pitcher (Mark Buehrle), which would you take? Carlos Silva is an extreme example, but there are plenty of guys that get by quite successfully allowing contact. This almost reminds me of the Kazmir/Shields debates of 2-3 years ago. I always took Kaz’s back thinking you could find a Shields anywhere.

Point being, with our defense, Buehrle might be the better option than De La Rosa.

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by Andy Hellicksonstine on Jan 14, 2010 12:45 PM EST up reply actions

This just happened to work out, but both those guys have K:BB of 2.33

MB=4.43:1.90, contact=86%,
JDLR=9.39:4.04, contact=74.8%

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by Andy Hellicksonstine on Jan 14, 2010 12:47 PM EST up reply actions

Isn't De La Rosa an extreme groundballer?

by R.J. Anderson on Jan 14, 2010 12:49 PM EST up reply actions

Nope, both are relatively equal.

by R.J. Anderson on Jan 14, 2010 12:50 PM EST up reply actions

All I'm saying is that if we were targetting a FA (we have no need to do this with our farm) a smart organization

would target the Buehrle’s of the world, even if the De La Rosa’s have sexier K numbers. If we were less adept at fielding, I would be all for De La Rosa

I'm a writer.

by Andy Hellicksonstine on Jan 14, 2010 12:56 PM EST up reply actions

Let's try this.

Say you have two pitchers who face 1,000 batters in a season (yes that’s a high number, but it’s just for math purposes).

Pitcher A walks 5% of batters faced and strikes out 12%.
Pitcher B walks 10% and strikes out 24%

Assuming both have identical home run (we’ll say 2% of total batters faced) , fly ball, and groundball rates, then Pitcher A is allowing more balls in play than Pitcher B, but also allowing fewer base runners, right?

Well, assuming we don’t have any HBP, SF, etc., that means PItcher A allows 810 BIP and PItcher B allows 640. If both have BABIP of .295, then Pitcher A allows 50 more hits. Amusingly, that wipes out the 50 walks.

Now that’s not perfect because you can argue that Pitcher A/B allows weaker contact or whatever, but those are basically Buerhle and Kazmir’s career ratios.

by R.J. Anderson on Jan 14, 2010 12:58 PM EST up reply actions

There's about a million different variables I didn't account for.

Oh well.

by R.J. Anderson on Jan 14, 2010 1:01 PM EST up reply actions

Nice nip in the bud

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by FreeZorilla on Jan 14, 2010 1:21 PM EST up reply actions

And a good defensive team (lets say they turn 71% of BIP into outs) vs. a bad defensive team (69%, hypothetically)

Pitcher A on good defensive team would have 830 BIP with 589 of them turning into outs, leaving 241 hits + 50 walks. That’s 291 baserunners vs. 709 outs, or a .291 OBA.

Pitcher B on good defensive team would have 660 BIP with 469 of them turning into outs, leaving 191 hits + 100 walks. That’s still 291 baserunners vs. 709 outs, or a .291 OBA.

Pitcher A on bad defensive team would have 830 BIP with 573 turning into outs, leaving 257 hits + 50 walks. 307 baserunners vs. 693 outs, or a .307 OBA

Pitcher B on bad defensive team would have 660 BIP with 455 turning into outs, leaving 205 hits + 100 walk. 305 baserunners vs. 695 outs, or a .305 OBA.

Pitcher B has a decided advantage on a poor defensive team. That is where he should go, making Pitcher A, relatively more affordable to a good fielding team, that has the option to go either way. Of course this leaves out SLG, but the hypotheticals that you gave me didn’t provide any knowledge of what the base hits were like. Assuming same HR rate, if pitcher B gives up more XBHs than pitcher A, then SLG would point towards pitcher A as the better performer. The converse is also true. It seems to play out as a pretty nice example of game theory.

I'm a writer.

by Andy Hellicksonstine on Jan 14, 2010 1:21 PM EST up reply actions