Explaining the weirdness of Kawhi Leonard’s impact on the Spurs defense

A recent article by CBS Sports' Matt Moore focused on the Spurs' defense with Kawhi Leonard on and off the court. The findings were surprising: San Antonio defensive numbers are much better when Leonard rests.

Moore explains why that might be. You should really, really read the entire article because it's great, but the gist of it is that opponents put Kawhi's man in a corner and go 4-on-4.

That seems to explain why units featuring the two-time Defensive Player of the Year are not doing so well on defense. The question that is still unanswered, however, is why are units not featuring Leonard excelling on that end.

Moore wonders about that but offers no explanation, so the PtR staff took a crack at trying to explain what happens.

Why are units that don't feature Kawhi Leonard doing so well on defense?

Eli Horowitz: Moore's piece is excellent, but that's actually the one question I didn't quite get. Isn't the answer that with him out, it goes back to 5-on-5 halfcourt with less space for the offense, versus 4-on-4 with Leonard being hidden in the corner?

With the starters in, sometimes it's almost 3-on-3 when opponents do this because they can also have Green in a corner, forcing Parker and either Aldridge or Gasol to guard pick and rolls in space.

On a related topic, I think this analysis points to an important question: is Pop willing to bench Parker and Gasol in the playoffs or meaningful regular season games? Doing that would neutralize this strategy as the upgrade on defense to Patty Mills and Dewayne Dedmon is huge.

Jesus Gomez: Eli is right. Most of the good defensive lineups that don't include Leonard include Dedmon or Patty. There are fewer weak links. It's probably just that simple.

There is something weird going on when Kawhi rests, though: Opponents are missing a ton of three-pointers.

They are shooting over 38 percent with him on the court and 24 percent when he's resting. The percentages are down all over the floor, including the corners, which could mean that the Spurs are just getting lucky.

If that's true, then at some point the bench units are going to struggle on defense and the splits with Leonard on and off the court will stabilize.

The bad news is that would mean the Spurs as a team are worse on defense than they currently seem.

Mark Barrington: I don't think it's that much of a mystery. When Kawhi is in the game opponents use the strategy Moore describes to make it a 4-on-4 game, and of those four, two are not good defenders. It's not just an advantage talent-wise, any set is also much simpler to execute with fewer players in the mix.

With Kawhi on the bench, they have to play 5-on-5 against a unit that has no weak points. True, none of the players are great on defense, but they are all about equally good. So the opposing team has to execute better for longer than in the 4-on-4 scenario, which most teams can't do as well as simple ISO and pick and roll plays.

Bruno Passos: I think the Kawhi Island evidence is interesting, but I don't think it reconciles nearly enough of what's going on with those numbers, nor do I think it's representative of what opponents are doing most of the time against the Spurs.

Leonard's defensive field-goal percentage is 48%, which is high for a wing defender (and MUCH HIGHER than his 39.2% DFG last year). Opponents this season are shooting 3.6% better from the field when he's the primary defender than they would otherwise -- that doesn't have anything to do with them playing 4-on-4 and speaks more to a fundamental performance issue.

It's fair to assume Leonard's defense might (at least temporarily) take a step back as he focuses more on his offense. It takes more effort for a wing defender to make as much impact as a big man, who is able to prove his worth by protecting the rim. That speaks to what kind of a force Leonard was in his two DPOY seasons.

This year, Leonard's been less immune to blow-bys and we've seen him caught sleeping more often than in years past (including in the Butler cut that Moore shared in his article). Overall, I'd say his on-ball defense has been a little worse, and his ability to impact a game with his help defense has (in part, because of the Kawhisolation stuff) been lessened a bit. Also, Tim Duncan and Kawhi Leonard were by far the team's best defenders last year. With one of their starters gone and the other in what may be a down year -- at least on the defensive end -- it's fair to expect that units used to relying will suffer as they adjust.

I think it's likely that Kawhi will re-calibrate and the Spurs will begin to scheme better as the year rolls on. And, like many people, I think more Dewayne Dedmon would help a lot. That, combined with those crazy three-point splits that Jesus mentioned, and I think the on/off numbers will start looking more normal in a few months.

J.R. Wilco: I loved Moore’s article and thought it was a well-written explication of a theory that explains a lot of weirdness in the Spurs defensive numbers so far this year. But it’s just a theory, and like Bruno I don’t think it will hold water as the season progresses.

First, there’s no doubt that some teams occasionally sacrifice whomever Leonard is guarding to go 4-on-4. But they really aren’t doing it that often. That doesn’t mean it’s not an issue, because in late game situations, or against contending teams in the playoffs, that could be the difference between a win and a loss. But in order for the Kawhisolation to explain why Leonard’s on/off numbers are the worst on the team, we’d need to be seeing teams going away from Kawhi for the majority of the time he’s playing, and that’s just not the case.

Second, some of the plays that Moore uses aren’t exactly crises for San Antonio. For example, the Bulls put Butler (and therefore Kawhi) on the side, but still ended up attacking Danny Green and LaMarcus Aldridge with a pick and roll. As a Spurs fan, I’ll live with that. It’s certainly not the potential disaster that’s Parker-Gasol defending the P&R.

Finally, sometimes numbers get strange and there’s nothing you can do. My first year running PtR, the Spurs went from best in the league to among the worst in 3pt% defense — and no one ever came up with a reason why. Last year, the Spurs were nearly last in the league in pace, even though they pushed the ball at every opportunity. Green couldn't buy a three last year, and this season he’s back to his career average. This year, players are shooting better when Kawhi guards them. That’s downright insane, but it’s unlikely to continue for long.

I think the amplitude of the weirdness is likely to lessen, and while it’s certainly interesting to investigate whenever crazy stats rear their ugly heads, I think it’s premature to draw conclusions after a quarter of a season.