The NBA standings tell lies. Not about every team, and not so much that they’ll make the worst team in the league look like the best, but for a handful of clubs every season, the standings do a poor job conveying actual performance on the court.
What causes these fibs? In large part, they arise because a team’s underlying statistics do not correlate perfectly with its actual results. But those same stats can help predict future results. Point differential and Pythagorean records—or, a team’s expected record based on point differential—are better predictors of a team’s future record than its actual record.
(How much better is Pythagorean record? A model using both regular and Pythagorean winning percentage to predict future winning percentage weights the latter four times more heavily.)
On the eve of the 2020-21 season, let’s take a look at four teams that had notable discrepancies last season between expectation—based on point differential and related metrics like record in close games—and their final record, and how these contenders might not be quite what they seem. We’ll start in Dallas, where the Mavericks embody this principle more than any other team.
2019-20 record: 43-32
2019-20 Pythagorean record: 48.4-26.6 (-5.4 actual wins vs. expected)
Record in one-possession games: 2-11
The Mavericks were the NBA’s unluckiest playoff team last season: They landed the West’s no. 7 seed, but by point differential, they were closer to the Lakers and Clippers than any of the West’s other playoff teams.
That kind of extreme underperformance doesn’t matter for this season. Since the introduction of the shot clock, both the biggest overachievers (teams that outperform their Pythagorean expectation by at least 5 percentage points) and the biggest underachievers (teams that fall short by at least 5 percentage points) have regressed to the mean the following season, meaning their over- or underachievement doesn’t carry over.
Pythagorean Divergence a Year Later
|Subset of Teams||Year X||Year X+1|
|Subset of Teams||Year X||Year X+1|
|Teams in the Middle||-0.1%||+0.0%|
For instance, the largest overachiever in the 21st century is the record-setting 2015-16 Warriors, who won 73 games versus just 65 “expected” wins. After adding Kevin Durant, they had an even better underlying performance the following season—but fell to 67 wins, precisely their expectation by point differential.
On the other end, the largest underachiever this century (and the second-largest in history) was the 2011-12 76ers, who won 35 games in a shortened season, versus 43 “expected” wins. The following season, the 76ers actually overachieved, with 34 actual versus 31 Pythagorean wins.
Dallas’s greatest issue was its performance in close games. The offense that set league efficiency records ranked just 26th in clutch situations, and the Mavericks went 2-11 in games decided by three points or fewer—one of the worst marks ever for an otherwise winning team.
But record in close games is also a fluky stat that regresses to the mean over a large enough sample. There is nothing to suggest ineffective clutch teams in one season will remain ineffective the next. In the 3-point era, the correlation of record in one-possession games from one season to the next is just 0.1, on a scale in which 0 represents no relationship and 1 a perfect relationship.
Before last season, 32 teams in the 3-point era had won 20 percent or fewer of their one-possession games, like the Mavericks did in 2019-20. Yet that same group of teams won nearly half of its close games in the following season.
The Worst Teams in One-Possession Games, a Year Later
What does that history mean for Dallas? Well, if the Mavericks had gone even 5-8 in those close games instead of 2-11, they would have been the West’s no. 4 seed instead of finishing seventh and facing the Clippers in the first round. And that assessment comes even though Luka Doncic and Kristaps Porzingis missed time with injuries. So as the Mavericks enter the 2020-21 season, even with Porzingis still recovering from surgery, it makes more sense to think of them as one of the leaders of the West’s non-L.A. contingent than a typical no. 7 seed trying to inch higher.
It’s possible that the Mavericks are irrevocably ruined at the end of games—but it’s far more likely that in a small sample of scattered close games, they just had shots rim out at the wrong times. They didn’t have any notable clutch issues in 2018-19, when they finished 7-7 in one-possession games and rookie Doncic was one of the league’s best clutch players. Doncic’s clutch performance fell off in his sophomore season, with his clutch effective field goal percentage dropping from 51 to 40 percent. But the guy who made this shot in a playoff game will probably win more than two close games this season.
2019-20 record: 34-39
2019-20 Pythagorean record: 37.0-36.0 (-3.0 actual wins vs. expected)
Record in one-possession games: 4-8
Thanks to the Suns’ undefeated record in the bubble and trade for Chris Paul, hopes are high in Phoenix, where the home team hasn’t reached the playoffs since 2010. The team’s underlying 2019-20 performance suggests they should be even higher.
Like the Mavericks, the Suns played better than their record indicates; unlike the Mavericks, that accompanying drop in the standings meant Phoenix missed out on the playoffs entirely. But to reach the postseason field in 2021, the Suns don’t really need to make a huge leap—they were already playing like a playoff club, with a better point differential than Portland, Memphis, New Orleans, and all the other second-tier Western teams targeting the no. 8 seed.
Notably, the Suns looked better than their record even before the bubble. The team was 26-39 when the season went on hiatus, but at that juncture, they had the point differential of a 30-win team.
Rosters aren’t static season to season. But unlike, say, the Pelicans, who are counting on a full season of Zion Williamson to propel them into the playoffs, the Suns made key offseason additions to a roster that, statistically, already profiles as a playoff team. Phoenix signed Jae Crowder and traded for Chris Paul, a reigning All-NBA honoree and one of the most efficient clutch guards in the league. (The Thunder led the league in clutch offensive rating last season, and the Rockets led in 2017-18.) Deandre Ayton is back for a full season, too, after being suspended 25 games for a positive test of a banned diuretic. Vaulting into the actual bracket this season shouldn’t be as much of a challenge.
Los Angeles Lakers
2019-20 record: 52-19
2019-20 Pythagorean record: 47.9-23.1 (+4.1 actual wins vs. expected)
Record in one-possession games: 7-3
No statistic mentioned in this section is a knock on the Lakers’ championship hopes come playoff time; barring injury, the team with LeBron James and Anthony Davis will surely enter the postseason as the betting favorite to repeat. But the Lakers’ regular season outlook is murkier, as the team is far from a sure thing to grab the no. 1 seed again. (And the top seed should matter more this season than last, with home-court advantage returning outside the bubble.)
As a reminder, here is what the actual standings looked like for the West’s top seven teams last season.
Top of the Actual Western Standings, 2019-20
But here is how the standings would have looked if every team played precisely to its point differential. Even with Kawhi Leonard and Paul George missing plenty of time, the Clippers were the most impressive regular-season team, and Dallas wasn’t far from the Lakers, either.
Top of the Pythagorean Western Standings, 2019-20
|Team||Pythag Wins||Pythag Losses||Games Back|
|Team||Pythag Wins||Pythag Losses||Games Back|
The Lakers were lucky to win as many games as they did a season ago, given their underlying numbers, which isn’t an easily replicable feat—even for LeBron. Although his teams have overperformed more often than not in recent seasons, this isn’t a career-long pattern by any stretch. Usually his teams’ actual records are right around their Pythagorean records; over his whole career, the average is just 1.4 extra wins per year. His teams have never overachieved by a large margin multiple seasons in a row.
So for the 2020-21 regular season, the Lakers don’t begin with such a large advantage over the rest of the conference as their record (and subsequent playoff performance) suggests. The team’s relative lack of rest after a shortened offseason could stunt their chances for the no. 1 seed, too, if James and Davis choose to conserve more energy for the coming postseason.
The team’s offseason acquisitions should help, with Montrezl Harrell and Dennis Schröder picking up any scoring slack if the stars rest. But like with the Warriors in Durant’s first season, even if the new veterans make the Lakers better under the surface, the team’s record might not reflect that improvement.
2019-20 record: 46-27
2019-20 Pythagorean record: 41.3-31.7 (+4.7 actual wins vs. expected)
Record in one-possession games: 9-5
The Lakers didn’t enjoy the largest overperformance versus point differential last season; that honor goes to the Nuggets, the team they beat in the Western Conference finals. The Nuggets also outperformed their Pythagorean record the previous season, by 2.8 wins. Maybe they have a secret strategy to overachieve every year? Nope! Go back any further and that gap disappears.
Across the whole league, in fact, teams do not consistently over- or underperform their point differential. Over the last decade, every team’s cumulative record has huddled close to its cumulative Pythagorean record—except the Timberwolves, who have somehow lost 39 wins versus expectation, more than three times worse than any other team. (The Wolves’ annual underperformance began as soon as they traded Kevin Garnett; perhaps they’re cursed.)
After their playoff romp, the Nuggets are the natural next candidate to challenge the two L.A. teams atop the West. But look at those Pythagorean standings from last season again: The Nuggets are starting from a similar baseline as the Rockets and Jazz—who, remember, came one shot away from knocking out Denver before that magical playoff run could even begin.
If Michael Porter Jr. improves as much as the Nuggets hope, and if Jamal Murray retains all of his postseason gains, perhaps this underlying concern will be moot.
But it’s important not to grow too excited about a handful of playoff games while downplaying the 73 regular-season contests that came before. In the Nuggets’ case, even the playoffs may be a bit deceiving, as they were actually outscored over their 19 games. They have a lot of exciting young talent, but there’s reason to be cooler on their chances in 2020-21.