Well, that didn't take long. One day into the two-month NBA postseason, aggrieved teams were already, well, crying foul over a disparity in referee whistles. Last Saturday in Chicago, Bulls guard Derrick Rose attempted more free throws (21) than the entire Pacers team (17). The same afternoon in Miami, the Heat went to the line 39 times to the 76ers' 15. That night in Dallas, the Mavericks took 19 foul shots in the fourth quarter, 13 by Dirk Nowitzki, who hadn't been to the line once in the first three periods. Dallas's opposition, the Blazers, shot two fourth-quarter free throws. The next night in Boston the Celtics beat the Knicks with a Ray Allen three-pointer that followed a controversial off-the-ball offensive foul on Carmelo Anthony. Portland coach Nate McMillan may as well have been speaking for all the slighted teams when he told reporters, "It's hard for our guys to know how to play out there when it's called a little different."
It's probably little comfort to McMillan et al., but this discrepancy in calls is entirely predictable. In our recent book Scorecasting, Tobias Moskowitz and I asserted that while there's nothing corrupt or conspiratorial going on—it's basic human behavior—referees are, in fact, biased. And this bias, thrown into such sharp relief last weekend, most likely will be present throughout the playoffs.
For years, fans (and the odd Dallas owner) have griped that the league's most marketable players get more calls. It's overly simplistic to look at foul shots and deduce that stars get preferential treatment. Nowitzki, for instance, has the ball in his hands a disproportionate amount of the time, especially late in the game; naturally, he'll shoot free throws at a disproportionately high rate. But we found that on "50-50" balls (loose balls, up-for-grabs rebounds, etc.) between stars and nonstars, the stars receive favorable calls almost 60% of the time—even more, if the star is in foul trouble. So, it stands to reason that stars do get special treatment late in the game. When the Heat boasts three stars and the Sixers have none, well... .
What's more, as in all sports, the home team in the NBA wins the majority of the games. We argue it's largely the result of the officiating. Even controlling for the quality of the opponent, home NBA teams shoot more free throws, get called for fewer fouls and commit fewer turnovers than the visiting opponent. Obvious calls, such as shot-clock violations and kicked balls, are equal; it's the judgment calls—such as Anthony's foul, or the noncall on Kevin Garnett's physical screen to free Allen for his game-winner—that go the home teams' way. This disparity is especially pronounced when there's a big crowd and when the games tighten, i.e., in the fourth quarter of a playoff game.
April 24, 2011
And maybe there resides some small bit of consolation for the Blazers, Pacers, Sixers, Knicks: In a few days they'll be the home team.
Now on Twitter
For up-to-the-minute NBA news, follow @ChrisMannixSI and @SI_LeeJenkins.
On the Grizzlies-Spurs series, which Memphis leads 1--0 after Sunday's 101--98 win:
"Memphis has to muck this series up and control every possession. Tim Duncan is great, but the Grizzlies have two bigs in Zach Randolph and Marc Gasol who are scoring machines in the paint. Fast guards kill them, and the Spurs have one of the fastest in Tony Parker. Mike Conley has to keep him out of the lane and off the free throw line. The same goes for Manu Ginóbili [who missed Game 1 with a sprained elbow but is likely to play in Game 2]. Memphis has two really smart perimeter defenders in Tony Allen and Shane Battier. If they can keep San Antonio under 40% shooting and control the paint, they have a shot."