---

Posted by Josh Shepardson at 2:40am (4) Comments

Do we use luck and randomness as a crutch?

On Wednesday, I posted an (entirely self-serving) article over at the CardRunners site, which could be summed up as half whining about my bad luck and half praising myself for entirely rebuilding my roster to compensate. In other words, nothing you'll find interesting.

One of the commenters on my post, however, was leaguemate Chris Liss of RotoWire. One of his comments in particular stuck out, so I wanted to repost it here and then respond:

Dave Cameron had a good post about randomness in which he used the clearly random example of the NFC winning 14 straight coin tosses to illustrate that Dan Haren's .350 BABIP could in fact be dumb luck and not have any cause, e.g., bad mechanics, tipping pitches, etc. that people tend to ascribe in those situations. And that's entirely true. BUT—it's also wrong to assume that his .350 BABIP must be dumb luck. It might well be, and it might not be. There could be a problem with his location, mechanics, etc. that partially or entirely explains it.

I think a mistake that a lot of the sabr community makes is to assume that bad pitcher BABIP is always bad luck, or bad HR/FB rate is always bad luck. Sometimes, there is something wrong.

In fact, Todd Zola sent me BABIP data by count—and BABIP goes up reliably as the count gets more hitter favorably – like .315 on 3-0, and .285 on 0-2. It's .305 on the first pitch. So let's say a guy like Haren (or Aaron Harang or Dave Bush) gets a rep as an extreme strike thrower—then batters might swing more often at the first pitch, rather than take a pitch and get behind.

There are probably better examples out there, too—just wanted to point out that not everything that might be luck is in fact luck. The hard part is figuring out which is which.

I'll absolutely agree with Chris that what may look like bad luck can—sometimes—be a legitimate problem. What often goes unnoticed is that part of what we "sabr" folk consider statistical regression to the mean is, in actuality, players making adjustments. If a player truly is tipping his pitches, he's either going to be out of the big leagues before we can see him "regress" or he's going to make the necessary adjustments to stick around long enough for us to actually see him "regress." Of course, that's not all that regression to the mean is—part of it truly is just mere statistical theory in the mold of Dave Cameron's coin flip analogy — but it is definitely a part.

The Haren example

In Chris' comment, he says, "I think a mistake that a lot of the sabr community makes is to assume that bad pitcher BABIP is always bad luck, or bad HR/FB rate is always bad luck. Sometimes, there is something wrong." While this is absolutely true, Chris has made it seem (at least to me) that the instance where "something is wrong" comes along more often than it actually does, or more often than we're truly able to identify it.

Perhaps he's just taking this stance because he perceives the guys on the other side of the argument to hold the polar opposite view, and his actual views are more balanced, but I think, in this instance, Chris is overstating how often the "there is something wrong" scenario actually occurs. To continue using Haren as our example, let's lay out what we know:

1. Haren has posted a .355 BABIP to this point in 2010
   
2. With a career BABIP of .305 career over 1,400 innings, his 2010 figure is very abnormal
   
3. It takes roughly six full seasons for BABIP to normalize

Given these known facts—six full seasons!—you're going to need to show me some very compelling evidence that Haren will not regress. That's not to say that the evidence doesn't exist, just that if we're not buying into a Haren regression, we're either being extremely foolish or we have some very convincing evidence at our fingertips. It's entirely possible he's tipping pitches or is having trouble with his mechanics, but the odds of him regressing are simply too great to ignore if we don't have proof to the contrary.

The one other thing we need to consider is that if Haren is indeed tipping pitching or struggling with his mechanics, it's highly unlikely that it would only manifest itself in his BABIP. Analysts will often say that BABIP is all luck, but that's not really the case. If we were to put a Little Leaguer on the Diamondbacks and allow him to throw 200 neutral-luck innings, I guarantee you he's posting a BABIP above .500. BABIP is in large part luck given that the pitcher in question is a bona-fide big leaguer.

In the case of the Little Leaguer, that .500 BABIP is going to come along with an 0.0001 K/9 and a 15.0 BB/9. He's not a legitimate big leaguer, so a high BABIP is expected. Haren, though, is posting monster strikeout and walk numbers. Guys who post monster peripherals don't consistently have high BABIPs. It just doesn't happen. I defy you to show me one example in the history of baseball of a pitcher with a 9-plus K/9 and sub-2 BB/9 but whose BABIP stayed over .350 in the long run.

And even if we're only talking about the short-term here, if Haren's high BABIP is a result of tipping pitches or doing something that bona-fide big leaguers can't get away with, it's highly unlikely that he'd also have peripherals worthy of a 3.32 xFIP—because those problems would affect his other numbers too! While it might be "wrong to assume that his .350 BABIP must be dumb luck," it's highly, highly probably that it is dumb luck. Unless you can show me evidence that it isn't.

More musings on luck and randomness

This ties in with another of Chris' comments on the CR post:

I will take issue with one premise though that I think is not entirely true—when your players play worse or better than they have historically that is not bad luck... it seems like people are alleging that buying a breakout player is dumb luck. It's not. Maybe you couldn't predict the extent to which he'd break out, but for example, as loathsome as it is for me to give Eric any credit, he deserves it for rostering Josh Hamilton. And he's entitled to whatever massive numbers Hamilton puts up even if he didn't specifically foresee them because that was part of the bargain he made when he bought him—that possibility.

Without getting too heavily into this (I disagree that players over or underperforming projections is completely independent of chance), I wanted to delve just a bit into distinguishing when we are truly predicting breakouts and when we're merely getting lucky—and deciphering one from the other is no easy task.

I think fantasy analysts—and I'm implying no one in particular here—sometimes fall into a confirmation bias trap of seeing their breakout picks pan out and automatically calling it a success, even if the original analysis supporting the pick was shotty.

While I'm picking on Chris (kidding; I'm not really picking on Chris), one example of a breakout player that jumps to mind is Ricky Romero, who Chris drafted and has trumpeted his success with. Not to imply that the analysis was "shoddy" here (I don't know what Chris' analytical process with Romero was), but if we're going to take credit for predicting Ricky Romero's breakout, I think we need to make it clear why we thought he would break out. And it needs to be more than just "the ground ball rate last year really jumped out at me." Dana Eveland had a better GB percentage than Romero last year, but he hasn't broken out (quite the opposite, actually).

Again, this isn't meant to be a shot at Chris in the slightest. I've made it clear in the past that I have a lot of respect for Chris, and he is the one winning the CR league right now. I'm quite sure there was more to it with Romero than just "he has a good groundball rate." I would be interested in hearing about it, though.

My point is that I think we, as fantasy analysts, should be held accountable for our analysis and predictions. Or at the very least, we should need to explain our reasoning if we take credit for predicting a breakout.

Radio appearance

For those interested, I'll be appearing on RotoWire's radio show today at 11:30 am EST to talk with Chris Liss about these sorts of things.