In the strictest sense, the San Antonio Spurs’ first round victory over the Dallas Mavericks should be considered a monumental achievement. A 2-7 upset should be praised in the highest regard. A pauper bested a prince! David toppled Goliath! The spunky underdogs with hearts of gold took down the evil billionaire!
Only it wasn’t. The Spurs’ win was a nice dose of revenge for the Mavs’ smackdown of a hobbled San Antonio team in last year’s playoffs, but this series may not have even been an upset. You’d be hard-pressed to find a more evenly matched series between a 2-seed and 7-seed, and each game reflected the balance between the two. The Spurs rightfully won the series in six, as their drastically improved health and the incredible parity among Western Conference playoff teams made the playoff seeding more than a bit misleading.
The intriguing underlying narrative of the match-up was win-loss record vs. statistical resume, as the Mavs boasted the superior record (hence the no. 2 seed) and the division-winner label, but the Spurs looked to be the more impressive team by slightly more complicated measures. For one, San Antonio’s point differential (considered by some to be the best predictor of playoff success) was far better (+5.1) than Dallas’ (+2.7), and was more in line with the West’s elite than borderline playoff teams.
Some have touted the Spurs’ series win as a victory for more advanced statistical measures; herein lies proof that win-loss record is not the best indicator of team superiority, and that other measures, even those as intuitive as point differential, could paint a better picture for comparative purposes. Better teams don’t just win more often, but their wins are of a fundamentally more valuable nature.
The irony here should not be lost on anyone. The Spurs, champions of the old guard, are, in this case, a poster team for the statistical revolution. Their victory over the Mavs can be explained away by the injuries or a Dallas collapse, but the data shows that the Spurs were the better team all along, even if they didn’t really hit their stride until late in the season.
It’s not just point differential, either. One of the more important tools of new wave statistics is the per-possession adjustment, a mathematical tinkering that renders pace irrelevant. It’s not about how many points a team scores in a game or even in x minutes, but how productive they are with a given possession. That’s why metrics like offensive efficiency (points scored per 100 possessions) and defensive efficiency (points allowed per 100 possessions) have become critical to the way that the smartest guys in the room are thinking about basketball. This game isn’t about total output, but rather how productive a team can be on a micro level. Every possession counts, and a team’s efficiency on a per-possession basis (either offensively or defensively) is ultimately what determines wins and losses.
Again, with the numbers in mind, the Spurs rightfully beat the Mavs. San Antonio’s efficiency differential (offensive efficiency – defensive efficiency; +5.23 points per 100 possessions for SA) was superior to Dallas’ (+3.96). All is well in the world of the spreadsheet.
Until the second round, which is where things really get interesting. The Spurs hold a slight edge over the Suns in point differential (+5.1 to +4.9), but when you break things down into per possessions measurements rather than per game? Phoenix (+5.81) has been the more efficient team this season, even if they only edge San Antonio (+5.23) by a slight margin.
Maybe the roughly half a point difference between the two teams isn’t enough to decide conclusively which team should take the series, but if we go strictly by efficiency differential in this case, the Suns are the favorite. They also hold home court advantage, which tends to make a difference in these seven-game affairs. If we’re not looking at the momentum each team has coming out of their first round series or the specific match-ups, the Spurs are the statistical underdog, if only barely.
In fact, if we look at the differential for each of Dean Oliver’s four factors (shooting as measured by effective field goal percentage, rebounding as measured by rebounding rate, free throw shooting frequency as measured by free throw rate, and turnovers as measured by turnover rate), the Suns own the advantage in all factors aside from rebounding.
Just like that, the Spurs have gone from de facto favorites to technical underdogs. Why is it, then, that this series feels like San Antonio’s to lose? Tim Duncan and Manu Ginobili played with a lot of confidence in the first round, and though plenty of the Spurs’ wins against the Mavs were close, they looked like a team in control. The Suns, on the other hand, wavered a bit during their matchup with the Blazers, despite their white-hot ending to the regular season. The Suns may hold the home court, but the Spurs seem to have every other intangible advantage.
This series should be interesting for a number of reasons, but keep the Suns’ statistical superiority at the back of your mind. Regardless of how both teams look right now, the more detailed numbers show that Phoenix is the slightly better team, even if raw point differential doesn’t.