Saturday, March 7, 2009

MoneyBasketBall

I believe I'm in good company, among stats oriented baseball fans, having read Michael Lewis' article on Shane Battier on February 13th.
Michael tells a fascinating story, but numbers don't appear in his writing (and I think they shouldn't). So I was curios and I did some checking, thanks to data provided at basketballvalue.com.
It's a quick and dirty work, but I think it's worth a look.

The following table shows how the Lakers perform with Kobe on the court, with Kobe off the court and with Kobe on the court against Battier and the Rockets (data from the full 2007/08 season).

Lakers production


pts/min off reb / min def reb / min poss/min pts/poss
with Bryant 2.29 0.27 0.74 2.01 1.14
w/o Bryant 2.08 0.29 0.70 1.94 1.07
with Briant
vs. Battier
1.79 0.32 0.70 1.90 0.94


Lakers scoring drops by 0.2 points per minnute when Kobe is sitting on the bench. Their possessions per minute drop to some extent too: this can be something done intentionally by the team (their best player is off the court, so they slow down the game pace to minimize the effect of the absence).
Something else may be going on, too: difficult shots that a superstar player can take (and make) are not taken by other players, thus needing a longer time for the team to find a shoting opportunity.
The slower pace when Bryant is off the court is not enterily responsible of the drop in points, as the points per possessions also go down a bit; the fact that LA grabs more rebounds under the opponents board when their star is out is likely due to worse shoting percentage.
When Battier is playing against the Lakers, and Bryant is on the court, LA sees a substantial drop, performing even worse than in other games with Bryant sitting on the bench (LA offensive rebounds rise, perhaps due to lower shoting percentages).

I add another comparison table.
Here is Lakers with Bryant vs Rockets with Battier compared to Lakers with Bryant vs Rockets without Battier.

Lakers (with Bryant) production VS Rockets


pts/min off reb / min def reb / min poss/min pts/poss
w/o Battier 2.02 0.26 0.74 1.97 1.03
with Battier 1.79 0.32 0.70 1.90 0.94


We see that LA (with Kobe playing) scores less against Houston (compared to what they do against the league), but Battier's presence on the court is what seems to bring Lakers offense down most.
Since basketball has a lot more interaction between players than baseball, we can't conclude that Lakers scoring less when Shane is playing is entirely Shane's responsibility. Maybe Battier is always playing together with a very good defenseman and they get benched together.

I only looked at scoring (with a quick glance at rebounding) because those were the data readily available at basketballvalue.com; there's another wonderful source of basketball play-by-play data (basketballgeek.com), where one can look deeper at the issues I presented.

No comments:

Post a Comment