Sunday, February 15, 2009

Shane Battier as the NBA's answer to "Moneyball"

I'm not completely sure what to make of this long Michael Lewis article extolling the Houston Rockets and their forward Shane Battier.

Lewis's treatment of Battier reminds me a lot of his treatment of Billy Beane in Moneyball. The idea is that Battier excels at things that aren't counted in the box score, and that makes affordable and underrated.

How so? Mostly on defense. Battier is said to cover the NBA's superstars exceptionally well. The evidence is mainly hearsay – the Rockets argue that they have a version of a "plus/minus" stat, the kind that figures out how the Rockets do when Battier is on the floor, and compares it to how the Rockets do when he's on the bench.

The stat is not a new one, and from what I've read, there are obvious problems with it, problems that Lewis acknowledges. Specifically, how the team does when a player is on depends on who he's playing with. You can control for that, but then you might wind up with insufficient data. For instance, if player A plays with B 90% of the time, then you wind up with only maybe three minutes per game when A plays without B. That makes the comparison difficult, because, first, you only have three minutes, and, second, you also have to take into account the quality of player C, who replaced player B.

There's nothing in the article on how that problem was solved, except this:

"[Rockets GM Daryl] Morey says that he and his staff can adjust for these potential distortions — though he is coy about how they do it — and render plus-minus a useful measure of a player’s effect on a basketball game."

Morey says that over his career, Battier is a +6, which means that, per game, when he's on the court, his team will score six more points than the opposition. I'm not sure if that's per 48 minutes, or per 33 minutes (Battier's average).

In any case, if you figure that Battier alone is worth 6 points per game, then, over a season, that's 492 points. At 30 points per game, which is David Berri's estimate in "The Wages of Wins," you get 16.4 wins. (Morey says the effect is larger, that +6 "is the difference between 41 wins and 60 wins." That works out to 26 points per win.)

How does Battier do it? According to Lewis, the Rockets have figured out players' strengths and weaknesses, and Battier tries to defend in such a way that the opposition is forced to do things they're weak at. For Kobe Bryant:

"When he drives to the basket, he is exactly as likely to go to his left as to his right, but when he goes to his left, he is less effective. When he shoots directly after receiving a pass, he is more efficient than when he shoots after dribbling. He’s deadly if he gets into the lane and also if he gets to the baseline; between the two, less so."

So what happens is that Shane Battier gets all this data before the game – he's the only player the Rockets give it to – and he tries to force Kobe into going to his left instead of his right.

"The ideal outcome, from the Rockets’ statistical point of view, is for Bryant to dribble left and pull up for an 18-foot jump shot; force that to happen often enough and you have to be satisfied with your night. “If he has 40 points on 40 shots, I can live with that,” Battier says. “My job is not to keep him from scoring points but to make him as inefficient as possible.” The court doesn’t have little squares all over it to tell him what percentage Bryant is likely to shoot from any given spot, but it might as well."

The effect, according to the article, is that when Battier guards Kobe Bryant, he does it so well that Kobe is rendered a below-average player.

Battier is also said to be "abnormally unselfish," and exceptionally good at playing the intangibles. "Instead of grabbing uncertainly for a rebound ... Battier would tip the ball more certainly to a teammate." "Guarding a lesser rebounder, Battier would, when the ball was in the air, leave his own man and block out the other team’s best rebounder." "He blocked the ball when Bryant was taking it from his waist to his chin, for instance, rather than when it was far higher and Bryant was in the act of shooting." "His whole thing is to stay in front of guys and try to block the player’s vision when he shoots."

Anyway, as I said, I'm a bit skeptical, still. I accept that Battier must be exceptionally good at defense, since (a) he plays 33 minutes a game and doesn't have very much in the way of traditional offensive statistics; (b) the Rockets have watched him and studied him and think he's great; and (c) his teams have done well. Still, from a scientific standpoint, the article is mostly anecdote and hearsay.

It shouldn't be all that hard to confirm the article's thesis and measure the size of the effect. If Kobe is good from one place but worse from another, that can be figured out by watching games and counting. If Battier holds him to those low-percentage shots when covering him, that can be counted too. And at the most fundamental level, can't you see what Kobe (and the other players) do when covered by Battier, and compare to what they do against the Rockets when Battier's on the bench? Something is better than nothing.

It's not really that I don't believe the Rockets. It's just that +6 points a game -- when it's acknowledged that Battier isn't all that great on offense – seems pretty high to me, and my instinct is to ask for more evidence.

Oh, and one more question for readers who actually know something about basketball (which I really don't). Assuming that everything in the article is correct, how much of Battier's value is due to his athletic skill? That is, suppose you took a league-average player and trained him to try to handle Kobe Bryant the same way that Battier does. Could he do it almost as well, or are Battier's instincts so good that he's exceptional in this regard?

(Hat tip: The Sports Economist)

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At Sunday, February 15, 2009 9:30:00 PM, Anonymous Anonymous said...

Basketball-reference has player splits against each opponent. Look at how well Kobe plays against Houston, and compare to how well he plays against everyone else.

Call FGA + .45*FTA a scoring attempt. Since 2007 (Battier's first season with the Rockets), Kobe is scoring 0.994 pts per scoring attempt against Houston, and 1.157 against everyone else. He is getting about about 31 scoring attempts per 48 minutes during that span. The difference between 0.994*31 against Houston and 1.157*31 against others = 5.0 pts/48 minutes, or 3.6/33 minutes. The +6 number doesn't seem out of line if they're talking about 48 minutes.

As far as offense, Battier is a player who may not do much, but also doesn't make mistakes. He doesn't turn the ball over, with a turnover percentage lower than Kobe's, and doesn't take bad shots, shooting 56% eFG% compared to Kobe's 49%. I could see how he would be a neutral player on offense.

At Sunday, February 15, 2009 9:48:00 PM, Anonymous Anonymous said...

A few points:

First, I suspect that the +6 means he is 6 points better over 100 possessions. So looking at it in terms of "per game" isn't exactly correct.

As for your question, the consensus (as the article points out) is that he is not a great athlete, but he has a very high basketball IQ. If you could get a more athletic player with the unselfishness and basketball IQ as he has then they would be very powerful indeed.

At Sunday, February 15, 2009 11:26:00 PM, Blogger Phil Birnbaum said...

Anonymous: Thanks, that makes sense! I never thought of doing that.

Ryan: Yes, I should have assumed that it was per 100 possessions. Thanks.

Also: is it basketball IQ, or is it just ... IQ? If the idea is to play guys a certain way, that might not require you to have special abilities to read how the play is unfolding, or such.

At Monday, February 16, 2009 4:53:00 AM, Anonymous Anonymous said...

All of Battier's success is due to his athletic skill. That is, if you took a league-average player and effectively trained him to handle Bryant the same way Battier does, that player would then be a better athlete. . .

At Monday, February 16, 2009 12:56:00 PM, Anonymous Anonymous said...

I loved that in the article "[Battier] doesn’t shoot much, but when he does, he takes only the most efficient shots", but his FG% is .381.

@Anonymous 9:30, Basketball-reference lists Battier's eFG% as .494 and Kobe's as .506.

At Monday, February 16, 2009 3:30:00 PM, Anonymous Anonymous said...

I wouldn't exactly distinguish between the two I guess, but he knows how to play the game.

Thus his understanding of basketball and how to maximize the *team's* chances of winning and to actually put that into action is a lot higher than other players.

At Tuesday, February 17, 2009 3:28:00 PM, Anonymous Anonymous said...

Having read the article, I get the impression that the Rockets' GM taught Lewis everything that Lewis knows and reports in the article ... but NOT everything that the Rockets know and Lewis reports in the article. And, to his credit, Lewis is intellectually honest enough to report as much in his 18-page work. Have the Rockets come across parameters that are not commonly measured but nevertheless give them an edge? If so, they aren't going to let Lewis know about it. Nor are they going to make their methods open-source.

At Tuesday, February 17, 2009 4:02:00 PM, Blogger Phil Birnbaum said...

Agreed. I don't mean to argue that the Rockets are wrong, just that we deserve more evidence than the article provides.

At Thursday, February 19, 2009 10:48:00 PM, Anonymous Anonymous said...

Using this, you can look at what areas Kobe shoots from when playing the Rockets and where he shoots from when playing everyone else. As a novice at basketball analysis (there's first time for everything), here goes.

The area directly under the basket is obviously the easiest area to score from and would be one area the Rockets would want to force him away from. Since the 2006-2007 season (Battier's first in Houston) vs. everyone except the Rockets, Kobe has taken 30% of his shots (by far the most in any area) from inside that region and posted a .617 shooting percentage. Against the Rockets, he still shot most often from that region, but it accounted for only 25% of his shots and the Rockets also limited him to a .415 shooting percentage. Not only did they (or Battier) keep him out of that area, but when they did let him in, they caused him to miss way more than he should have.

Kobe also shoots a lot of three-pointers. Against everyone but the Rockets, they account for 22% of his shots, and he shoots at a .359 clip. Against the Rockets, three-pointers account for 17% of his shots, and his shooting percentage drops to .326.

In the article, Morey repeatedly emphasized the efficiency of a three from either corner, and while Kobe doesn't take many shots from those areas (only 89 attempts, or 2% of his shots vs. everyone else since 2006-2007), he's only had one attempt from either corner vs. Houston. He missed it.

The Rockets have taken away 5% of Kobe's layups/dunk attempts and 5% of his three-point attempts. They're forcing Kobe to take more mid-range jump shots, which are by far the least efficient shots he can take. Even when they do let him take a more efficient shot, they are limiting his ability to actually convert it.

At Thursday, February 19, 2009 10:54:00 PM, Blogger Phil Birnbaum said...

Joe P: Thanks, that's awesome! That's the kind of stuff that I wish had been included in the article ... and it's interesting that nobody's analyzed stuff that way before. Your method sounds like a pretty decent way to start measuring defense. Of course, you can't always attribute that to a particular player, but it's a start to figuring out why a good defensive team is a good defensive team.

At Tuesday, April 30, 2013 7:04:00 AM, Anonymous P Smith said...

I ran across your item looking for stuff on Battier. Here's one stat that isn't shown by his play, only his presence:

In 2007-2008, the Rockets had a 22 game winning streak the second longest since the 1972 (?) Lakers.

In 2012-2013, the Miami Heat had a 27 game winning streak, now the second longest in the modern era.

Battier played for both teams.

Is that coincidence, or his effect on the team? I'd wager that Battier's presence by joining in 2011 had more of an effect on Miami winning the 2012 title than Lebron James. At 66-16 in 2012-13, a repeat looks likely.


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