San Antonio Spurs: Assessing the team’s top 10, yet still mediocre defense

Here at Air Alamo, we’ve recently touched on big picture issues regarding this year’s San Antonio Spurs. We’ve talked about their performance this year against our pre-season expectations of the team, the best performers of the young season, and also analyzed the underlying rebounding issues plaguing the team.

But one problem we haven’t yet addressed is the medium-sized elephant in the room — one that’s both big enough to cost the Spurs true championship contender aspirations and small enough to linger through the season if not adequately addressed. It’s time to address one of the most puzzling, under-talked about elements of the season: The Spurs’ pedestrian but not overtly terrible defense.

The San Antonio Spurs built their legacy on defense

Perhaps the oldest cliché in basketball is “defense wins championships.” As Spurs fans well know, this is true, as the team doesn’t win any of its championships without playing lockdown defense and scoring just enough points to win title after title. The anchor of those five rings, Tim Duncan, recently said as much himself on The Ringer’s “Real Ones” Podcast, attributing most of the Spurs’ success to being able to consistently hold teams to the 90s and below.

But this cliché has become so — well, cliché, that defense is often ignored. It’s not as sexy as the eye-popping dunk or the step-back three, never was, and never will be. But it feels like more than just that recently as the NBA’s continued evolution into a more offense-driven league over this past decade and a half make it harder and harder to stand by this old adage.

Next: How the Spurs' defense stacks up so far

The San Antonio Spurs’ defense so far

This season, the NBA team league average for points per game currently sits at 111.4, over 10 points more than during the Spurs’ last title run in 2014 (101.0), and just under 20 points more than the team’s first title run in 1999 (91.6).

Defensively, the Spurs fall right in line with this trend. The fact that the Spurs are not terrible has actually led to their play on this end slipping under the radar in a way that wouldn’t have likely happened then if the Spurs’ struggles were more evident on that side of the ball.

But stating the obvious, defense still matters. Samford University’s Courtney Williams pointed out in May 2019 the following:

18 out of the last 20 NBA champions had an opponent PPG lower than the league average, with 45% of [those] championship teams rank[ing] in the top 5 for opponent PPG and 70% rank[ing] in the top 10.” Williams adds, “even more telling is the fact that six of the last 20 championship teams had the lowest opponent FG% in the league, 13 were ranked in the top five, and 18 were ranked in the top 10.”

Those statistics still hold true two years later when adjusting per pace, as 18 of the last 20 champions ranked in the top 10 in defensive rating, with 12 of those teams ranking in the top 5. Still want that title? Then it’s time to defend.

As of now, the Spurs’ defensive numbers are solid but pretty misleading. The team is giving up 109.8 points per game, placing them right in the middle of the pack at 14th in the league. However, the Spurs also allow their opponents to shoot 46.5 percent against them, the 10th-worst rating in the NBA. Still, the team somehow manages to sit tied for the 9th-best in the league with a defensive net rating of 108.2

The misleading part is that just a few games ago, these numbers were substantially worse at 111.8 points allowed per game and 109.4 points per 100 possessions, placing them only at 17th and 15th in the NBA, respectively.

As much as Spurs’ fans would like to attribute this to improving on-the-fly, it’s no secret that playing the post-Harden, pre-Oladipo Rockets with John Wall missing distorted these numbers, making the Spurs’ defense look better than it actually is.

Even against the depleted Rockets, the Spurs still gave up 109 points in a surprising January loss. In game two of the series with Houston, the Spurs again played down to their competition, getting burned for 45 points by an undrafted rookie in Mason Jones and Ben McLemore.

Next: Diving into advanced numbers

The Strengths and weaknesses of the San Antonio Spurs’ defense

Looking more closely using NBA.com’s advanced team defensive stats, we see that the problem areas for the Spurs are precisely the areas that modern defenses are determined not to give up: layups and threes.

The Spurs do a great job contesting inside, limiting teams to the fourth-lowest percentage from five feet and 57.1 percent the 20.6 field goals per game they allow from that distances means teams are scoring 41.2 per game from under the Spurs hoop.

The 3-point shooting allowed is even more problematic because while the 12.1 made attempts the Spurs give up is 11th-best in the NBA, the 38.7 percent clip their opponents shoot ranks sixth-worst.

Luckily, the Spurs have excelled in keeping opponents off the line, as teams only get 20.4 trips to the line and make only 14.6 per game. Altogether, that means that the Spurs give up approximately 92.1 points from these three areas alone.

For the Spurs to return to a championship or even contending form, it’s time to do a better job limiting points coming from the three most analytically desirable spots on the floor. In part two of my series, I’ll look into just how they can do it.