How NBA Team Point Differentials Can Drastically Change the League's Landscape
Historically, point differential has been a better predictor of a team's following season record than their actual past record. There are a lot of factors that go into games, and sometimes teams could be on the wrong end of some bad luck.
For example, let's say a team plays a lot of close games (as your typical average team would do by nature of being average). There could exist a scenario in which this average team loses eight games in a row on last second buzzer-beaters. Now let's say another team gets blown out in eight consecutive games, losing by an average of 30 points in each contest. You can see how records can be a bit misleading - if you knew the context, you'd obviously say that the team losing from last second shots was far superior than the team getting blown out, despite the fact that their records matched at 0-8.
Over the course of time, anomalies like these get worked out, and records can eventually become more reflective of the truth. However, 82 games can be a small enough sample that it doesn't happen. This is how a team like the Minnesota Timberwolves had the point differential of an 48-win team, but only won 40 games last season.
Here are the point differentials and expected versus actual wins from last season in the Western Conference.
| Team | Points For | Points Against | Net | Expected Wins | Actual Wins | Difference |
|---|---|---|---|---|---|---|
| Grizzlies | 7,884 | 7,755 | +129 | 46 | 50 | +4 |
| Jazz | 7,791 | 8,379 | -588 | 22 | 25 | +3 |
| Trail Blazers | 8,753 | 8,426 | +327 | 52 | 54 | +2 |
| Lakers | 8,442 | 8,958 | -516 | 25 | 27 | +2 |
| Spurs | 8,639 | 8,006 | +633 | 61 | 62 | +1 |
| Thunder | 8,705 | 8,185 | +520 | 58 | 59 | +1 |
| Rockets | 8,829 | 8,455 | +374 | 53 | 54 | +1 |
| Mavericks | 8,597 | 8,400 | +197 | 48 | 49 | +1 |
| Nuggets | 8,559 | 8,735 | -176 | 35 | 36 | +1 |
| Pelicans | 8,177 | 8,399 | -222 | 33 | 34 | +1 |
| Suns | 8,629 | 8,413 | +216 | 48 | 48 | 0 |
| Clippers | 8,850 | 8,278 | +572 | 59 | 57 | -2 |
| Warriors | 8,549 | 8,155 | +394 | 54 | 51 | -3 |
| Kings | 8,241 | 8,479 | -238 | 33 | 28 | -5 |
| Timberwolves | 8,768 | 8,549 | +219 | 48 | 40 | -8 |
Since we're adding more time to our sample (two seasons is longer than one, obviously) when we look into the 2014-2015 season, we would expect the actual record next season to either rise or fall closer to the expected record, which is based on point differential.
Thus, it's likely that the Timberwolves and Kings would be much improved this coming season. Well, not really improved as much as having a record that is accurately reflective of their actual on-court production.
And this is important because of team perception. Let's say the Timberwolves hadn't been historically far from their expected wins, and had merely met it (we could even say in another parallel season they might exceed it). If that were the case, and everyone had met their expected wins in the West, the Timberwolves would have been tied for the eighth spot with a significant edge in net points.
If that had been the case and Kevin Love had made the playoffs for the first time in his still-young career, would he be so adamant about leaving the Timberwolves? There are probably many other reasons for him wanting to leave, but making the playoffs would certainly be an important factor.
And this also plays into what happens this coming season if the Timberwolves decide to not trade him prior to the season. We saw in Portland that LaMarcus Aldridge was unhappy right up until the Trail Blazers made the playoffs, and then he was all about staying in Rip City. Could the same thing happen in Minnesota?
I'm not around the organization, so I'm not sure whether things between Love and the front office have soured to the point that it doesn't matter. But if there's a chance that winning would help change his mind, the Timberwolves should keep Love (unless Wiggins truly is on the table, but that's another matter) and let records rise and fall back to the mean. They were supposed to be a 48-win team this year, and that was despite discovering their future rim-protecting center in Gorgui Dieng late in the season. It's not inconceivable to think that the Timberwolves make the playoffs next year. And then, who knows what happens?
