How the Spurs defense can be scary again

For the first time since before Tim Duncan arrived 22 years ago, the Spurs struggled to get stops last season. The reasons for their porousness aren’t particularly surprising. A lack of roster continuity combined with an overall talent shift to more offensive-minded players led to a disjointed effort from a group with limited upside on that end.

Their 20th ranked defense gave up 110.5 points per 100 possessions, a number that somehow still fails to capture just how easily opponents were able to score. The team’s poor performance on that end led to some rare sights at the NBA level, including a triangle and two defense that ultimately didn’t work.

The most obvious issue was perimeter defense. While conventional wisdom holds that, for the most part, wings and especially bigs bring much more defensive value than perimeter players, the 2018-19 Spurs put that notion to the test. The inability of the majority of the team’s guards to defend their position led to constant defensive breakdowns. Opposing guards scored 20 or more points on the team 64 times last season, the most in the league.

Bad defense on ball handlers tends to lead to penetration, a weakness that plagued the Spurs all season long. They allowed nearly 47 drives per game, 5th most in the league, and although they managed to hold the ball handler on drives to near a league average scoring rate, they allowed the 2nd most assists off drives, which underscores just how bad the team was at defending the drive and kick.

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*Data available here (derived from tracking data at nba.com/stats).

In fact, not fouling was pretty much the only thing the Spurs managed to do well on opposing drives. But the penetration itself wasn’t the biggest problem. As mentioned, they held ball handlers to a near league average scoring rate on drives, in large part due to the fact that they were so stingy with giving up free throws. The problem was bad help and poor discipline by the rest of the perimeter defense.

Recognizing that they couldn’t contain penetration, either individually or as a team, the Spurs spent much of the season searching for a way to keep opposing ball handlers out of the middle of the floor, frequently deviating from their typical scheme in hopes of hitting on something that worked.

Since many of the team’s perimeter defenders were unable to effectively fight through or lock and trail over screens, that meant more switching and going under screens, even in situations where the Spurs would typically seek to deny the screen entirely. While those adjustments generally had the intended effects, the adjustments themselves, as well as continued poor execution on the ball and in help, led to a cascade of threes.

Unsurprisingly, that resulted in a dramatic shift in the shot frequency of the Spurs’ opponents by range, per Cleaning the Glass:

cleaningtheglass.com

Not only did teams shoot more threes against the Spurs than ever before, they did so at a 36.5% clip, a little above league average. While there’s a lot of noise in opponent 3PT%, it’s pretty easy to figure out why the Spurs saw a jump in both opponent 3PT frequency and accuracy.

After giving up the 9th fewest wide open threes in 2017-18, they plummeted to 19th in 2018-19. That jump worked out to about 4 more wide open threes per game. That’s 4 more of one of the most valuable shots in basketball. Just turning those 4 shots back into midrange attempts, even uncontested ones, would’ve made the Spurs an average defensive squad.

However, this season should be much different. The Spurs will have their All Defensive 2nd Team point guard back, meaning they should be able to keep an elite perimeter defender on the floor at all times. That means instead of blow-bys, missed switches, and uncontested threes, there will be a lot more of this:

And this:

Dejounte Murray, in particular, will have a dramatic impact on the team’s defense. In 2017-18, Spurs’ opponents turned the ball over more, took fewer shots, and earned fewer free throws per 100 possessions when he was on the court. His ability to rebound and generate steals without fouling reduces the other team’s opportunities to score, and that’s without even considering how he closes driving and passing lanes, clogging up the offense and forcing more difficult shots.

The Spurs also added DeMarre Carroll in the offseason and should be giving some minutes to Lonnie Walker IV as well. DeMarre is a solid, reliable wing defender, and even though Lonnie has nowhere near the defensive pedigree of Dejounte or Derrick White, he has the physical tools to be an outstanding defender and should already be better than the rest of the guards on that end of the court.

These additions should mean far less penetration to begin with and less of a need to help off shooters when it does happen, which will lead to more contested floaters and midrange shots, which the Spurs’ defense is designed to allow. It should also mean much better rotations and close outs, extending possessions, and forcing opposing teams deeper into the shot clock.

The Spurs will still be playing some limited defenders, but with a healthy roster, they won’t be forced to play more than two at a time. With Dejounte and Derrick in the lineup, there’s no reason to play Patty Mills and Bryn Forbes together, and with DeMarre able to fill the nagging hole on the wing they were never able to solve last season, there will be no need to play DeMar DeRozan and Marco Belinelli together, either. Throw in minutes for Lonnie, and it becomes clear the Spurs could easily have two plus defenders on the perimeter for 48 straight minutes.

They will still likely have to make some concessions on defense to keep the offense running, so Patty or Bryn will almost certainly spend a handful of minutes on the court with DeMar or Marco. But that’s a far cry from needing to spend 1250 minutes with 3 of the 4 on the court, giving up over 113 points per 100 possessions, like they did last season.

If the team’s perimeter defenders can clean up their act — staying with their man on and off the ball, cutting out the overzealous help, and rotating just a half step quicker — the Spurs should be able to knock their opponents’ three point frequency back down to a more acceptable level. More importantly, if they can cut back the number of wide open looks they give up, preferably closer to 2017-18 levels, it’ll go a long way towards helping reestablish the dominant defensive presence that has been a hallmark of the team for the last 22 years.