Nylon Calculus: Lessons from the Spurs-Rockets regular season matchups

With the Houston Rockets and San Antonio Spurs ready to kick off their second-round series on Monday, it’s always interesting to see if we can glean any insights on the ensuing playoff matchup by looking back at the regular season battles between the two teams. The Spurs won three of the four regular season games this year, while seemingly stifling the Rockets’ high-powered offensive attack. Given these outcomes, should Houston be worried about their upcoming series against San Antonio, or does the context of their defeats make these results less concerning?

Before looking into their specific matchups this season, let’s take a look at the Spurs’ defensive philosophy. Here at Nylon Calculus, we preach that the best way to defend the 3-point line is to limit 3-point attempts from being taken, and San Antonio does this better than most defenses in the league (all while not fouling). Ultimately, the Spurs ranked No. 3 in limiting opponents’ 3-point attempts and free throw attempts in the regular season, a vital factor in the performance of the league’s best defense.

Turn to the Rockets’ offense, and you’ll see a team that emphasizes the exact shots that San Antonio doesn’t allow. Houston leads the league in 3-point attempt rate plus free throw rate, and looking at the chart below, it’s not even close.

So, when the two teams take the court for Game 1, these strengths will clash once again. In the four previous meetings this season, the Spurs held the Rockets to a 103.5 offensive rating (8.3 points per 100 possessions below their regular season mark). But before we chalk this one up to San Antonio’s schemes or personnel, let’s take a closer look at the context of these numbers.

The most glaring difference in Houston’s offensive output in games against the Spurs was the team’s 3-point percentage. The Rockets shot an abysmal 29.2 percent from behind the arc against the Spurs this season, posting a lower 3-point percentage against only four other teams (the Atlanta Hawks, Golden State Warriors, Indiana Pacers and Miami Heat). In the other 78 games in the regular season, Houston shot a much healthier 36.0 percent. So, have the Spurs dodged an unlikely share of bullets in games against the Rockets this season?

First, let’s look at the openness of 3-pointers that the Rockets attempted against the Spurs. From the table below, you can see that Houston tallied more open looks from behind the arc against San Antonio than their regular season average.

And the numbers also suggest that Houston attempted a higher quality of 3-pointers when considering the number of dribbles taken before their shots. In these games, the Rockets took more catch-and-shoot 3-pointers and less 3-pointers off of seven or more dribbles.

From these tables, it’s fair to say that Houston has manufactured roughly the same (and maybe even a slightly better) quality of 3-point attempts against the Spurs than the team normally produces. Now, looking beyond quality, the issue of quantity and whether San Antonio was able to limit the Rockets’ long-range attempts is even more critical to this investigation.

In their four games, the Rockets saw dips in both their 3-point attempt rate (down 1.9 percent) and their free throw rate (down 5.6 percent) compared to all other regular season games this season. However, the team’s 3-point attempt rate plus free throw rate in these games (69.5 percent) would still be the highest mark in the league.

Ultimately, Houston shouldn’t be worried about their regular season results against the Spurs, knowing that their offense was able to generate roughly the same quality of looks from behind the arc (along with an advantageous shot composition). Keep shooting and those shots should start falling eventually.

Sources: NBA.com/Stats, Basketball-Reference