Tag Archives: Moneyball

"Moneyball" in basketball

From the Washington Times

Basketball’s a team sport, and lots of things aren’t tracked,” Winston says. “Like taking the charge, going through a screen, tipping a ball to your teammate, saving a ball from going out of bounds. That’s where our system comes in. All these little things should translate into points.”

One problem: Traditional plus-minus systems tend to overrate average players on good teams and underrate good players on lousy ones. After all, a zero plus-minus rating on the Los Angeles Lakers is not the same as a zero rating on the Los Angeles Clippers, mostly because one team has Kobe Bryant and Shaquille O’Neal and the other has Marko Jaric and Chris Kaman.
To compensate, Winval’s ratings are weighted to take into account every other player on the floor. For every time segment a player is in a game, the system tracks the other nine players on the floor, the length of the segment and the score at the start and end of the segment.

The result of all that math? Rankings that sometimes refute conventional NBA wisdom. High-scoring players like Vince Carter, Dirk Nowitzki and likely MVP winner Kevin Garnett are among Winval’s top 10. But so is San Antonio’s Bruce Bowen, an unsung defensive specialist who averages just 6.8 points a game.
On offense, Bowen makes the defending league champs less than a point a game better than an average NBA player. On defense, however, the Spurs are 10 points a game stingier with Bowen on the floor.

Sacramento’s Brad Miller and Denver’s Nene fare well for similar reasons, while the Nuggets’ Anthony, the Kings’ Mike Bibby and New York’s Stephon Marbury rate lower than you might expect.
“Marbury’s one of the top 10 players on offense,” Winston says. “Everybody thinks this guy is a great player. But when he’s on defense, he gives it all back.”