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)