One more thing the Golden State Warriors are doing better than anyone
By Ian Levy
With their 109-105 win over the Atlanta Hawks last night, the Golden State Warriors now a win percentage of .915, the highest in league history. Assuming they maintain this pace, they’ll finish the season with 75 wins, smashing the 72-win mark of the 1995-96 Chicago Bulls. On February 18, six wins and a loss ago, FiveThirtyEight projected the odds of them surpassing Chicago as about 54 percent.
What’s interesting is that, despite currently holding the best win percentage of all time, Golden State does not have the best point differential of all time. They don’t even have the best point differential this season, that honor belong to the San Antonio Spurs who, along with the 1995-96 Bulls and both the Milwaukee Bucks and Los Angeles Lakers during the 1971-72 season, have outscored their opponents by a greater average than Golden State. Winning games is what ultimately determines playoff seeding and playoff advancement, but point differential his highly correlated and has been used in the past as a more accurate measure of team strength than win percentage.
Pythagorean win percentage is an estimation of what we would expect a team’s win percentage to be given their average point differential. The graph below plots all team seasons going back to 1990-91, the first championship for Michael Jordan’s Bulls, by their Pythagorean win percentage and their actual win percentage.
Obviously there is an extremely strong correlation between the two measures, although there are some outliers as well. It turns out that this season’s Warriors are tied with this season’s Memphis Grizzlies as the teams who have outperformed their expected win percentage by the largest margin — 10.1 percent. For the Warriors, that works out to about six more wins than we would expect across the season to this point, and eight across the full regular season. Essentially, Golden State’s chances of breaking the record are indelibly linked to their ability to win more than their point differential suggests they should.
So why, exactly, are the Warriors about six wins ahead of where we would expect?
The answer is in their ability to win close games, as we saw last night against Atlanta. So far this season, Golden State is 21-1 (a .955 win percentage) in games where the margin was five points or less at any point during the final five minutes of regulation or overtime. They have the best clutch offense in the league (125.1 points per 100 possessions) and the best clutch defense in the league (84.7 points per 100 possessions). Their per 100 possession point differential in the clutch this season is +40.4, nearly double the next best team in the league — the Dallas Mavericks at +20.8. The gap between them and the Mavericks is roughly the same as the gap between Dallas and the 13th-best team, the Atlanta Hawks.
Clutch performance itself carries with it a certain degree of random noise, but I think we can comfortably posit that the Golden State Warriors are well beyond that. They are not the first team to manifest a sustained run of clutch time excellence that nets some extra wins beyond expectations. However, no one has really done it like the Warriors have this year. Chalk it up to another piece of NBA logic and wisdom that the Warriors are completely remolding right in front of our eyes.