SAN ANTONIO — The Miami Heat were heavy betting favorites over the San Antonio Spurs before the N.B.A. finals began, despite computer rankings that showed the teams to be relatively even.
There were several reasons for this. First, the Heat were scheduled to have home-court advantage in four of the seven games. Second, the Heat won more games during the regular season, 66 to San Antonio’s 58. (The reason the teams’ computer rankings were about equal is because San Antonio played a considerably tougher schedule.)
But there was also the notion that the Heat had another gear — that they could elevate their performance to close out a game or a playoff series when they needed to. Now, down two games to one in the series and facing elimination if they lose games four and five in San Antonio, Miami will need to find its best basketball.
The Heat’s record in critical situations in the regular season was, in fact, extraordinarily impressive. The N.B.A. keeps statistics on what it calls “clutch time” performance, which it defines as situations in the last five minutes of the game when the score is within five points or less. In these cases, representing 176 total minutes of play, the Heat outscored their opponents 427 to 294. That’s the equivalent of beating an opponent 116-80 per 48 minutes, the length of a full N.B.A. game.
Stat geeks like me default toward skepticism about the notion that certain teams or athletes perform especially well in the clutch. Numerous studies of baseball, for example, have found that clutch hitting is a largely random phenomenon. And studies of basketball have found that fans tend to overrate the notion of the “hot hand”, misinterpreting essentially random sequences of field goals and free throws as being deeply meaningful.
At the same time, the case for clutch performance is perhaps stronger in the National Basketball Association than in any other sports league — and may reflect rational decision-making by teams and players as much as psychological factors. The N.B.A. has an extremely long season. It is considerably more physically demanding than a sport like baseball. And unlike N.H.L. players, who take shifts on the ice, the best N.B.A. players are on the court for the vast majority of the game. So N.B.A. players need to pace themselves — and it makes sense for them to conserve the most effort for when they have the most on the line.
Is there any evidence that the Heat do this more effectively than other N.B.A. teams? An N.B.A. team that wanted to maximize its number of regular-season wins would put more effort into games that it expected to be the closest. It could slack off some in games it was almost certain to win — for instance, in a home game against the Charlotte Bobcats — while perhaps being willing to concede some games in which it would be a clear underdog even if it played its best.
I went back through this year’s N.B.A. regular-season schedule and estimated the probability that each team would win each game on the basis of the teams’ power ratings and which team had home-court advantage. I then identified the games that projected to be the most competitive — those where neither team had better than a two-in-three chance (or worse than a one-in-three chance) of winning. These cases represent the rough equivalent of games in which neither team would be favored by more than four points in the point spread.
The Heat played in 21 such games during the regular season. Essentially, these were the toughest games on their schedule — road games against other playoff-bound teams, especially from the Western Conference, or home games against the very best teams in the league like San Antonio. (In only one instance — a road game in Oklahoma City in February — were the Heat assigned less than a one-in-three chance of winning, according to the formula. This game is excluded from the analysis, although the Heat won it 110-100.)
How well did the Heat do in these games? They went 14-7, winning two-thirds of the time. That reflects the best winning percentage in the league in games that seemed like even matchups on paper. Miami also outscored their opponents by a margin of 3.3 points in these games.
One qualification is in order: although these games were, by definition, relatively even, the Heat still rated as slight favorites in most of them, and would have projected to go somewhere between 11-10 and 12-9 in them on the basis of their overall power rating. So we’re talking about two or three extra wins, which is statistically not all that definitive.
Nevertheless, the evidence is consistent with the notion that Miami was saving its best performances for when it had the most to gain or lose – and the implication is that computer ratings that weight all games equally may underrate the Heat when it comes to key games.
So why hasn’t Miami’s performance carried forward into the playoffs? Actually, the Heat were doing just fine – until they encountered the Spurs.
San Antonio did not perform especially well in even-strength matchups during the regular season, going 13-14 in these games. However, under their coach, Gregg Popovich, the Spurs take the notion of timing their players’ performances to the extreme, resting their veteran stars whenever they can during the regular season to preserve their fitness for the playoffs – even at the price of drawing fines from the N.B.A. commissioner, David Stern.
Tim Duncan, for example, averaged only 25 minutes per game during the regular season (accounting for the fact that he sat out 13 games entirely) – but has played 34 minutes per game in the playoffs. Tony Parker’s minutes have increased to 36 per game from 27, while Manu Ginobili is playing 25 minutes per game instead of just 17. Although Miami’s “Big Three” – LeBron James, Dwyane Wade and Chris Bosh – are also playing more minutes per game, the increased playing time for the Spurs’ stars is far more dramatic.
If Miami loses the series, there are sure to be questions about whether the Heat burned themselves out during the regular season. But Miami may be every good as their 66-16 record implies, and perhaps even better in key games.
The Spurs, however, are practically a whole different team during the postseason. On the bas
is of John Hollinger’s Wins Added statistic, I estimate that the playing time allocations the Spurs are using in the playoffs make them the equivalent of 14 wins stronger than their record suggested during the regular season — tantamount to adding a star player like Blake Griffin to their lineup. Who needs clutch players when you have Popovich’s clutch strategy?