Nylon Calculus: Smart rotations are key to beating the Golden State Warriors
By Nick Sciria
The Golden State Warriors’ offense is unlike any other — unpredictable and free-flowing, yet disciplined and precise. Steve Kerr and company have infused complex actions into a clever read-and-react system, culminating in a masterful art piece of fluidity and movement. Now, the Warriors sit just four wins away from basketball glory, with only one team left to counter. And if the Cleveland Cavaliers are to successfully combat Golden State’s purring offensive machine, it will have to be through calculated defensive rotations (and prayers, prayers definitely help).
In last year’s NBA Finals, one of the most observable defensive strategies that the Cavaliers employed involved Harrison Barnes. Cleveland was content with Barnes firing away from 3-point range, and Barnes took what the defense gave him.
Despite this more favorable shot composition compared to the regular season, Barnes struggled mightily from behind the arc.
Using his regular season percentages and taking into account the openness of his shots in the Finals, we would have expected Barnes to make 40.2 percent of his 3-pointers. However, his rhythm and confidence issues seemed to grow stronger with every miss, and he made only 31.0 percent of his shots from behind the arc in the series.
Although this 9.2 percent difference might seem surprising, 3-point percentages are notably noisy. And in the 2016 NBA Finals, the Cavaliers experienced the fortunate side of this noise in Barnes’ 3-point shooting. Generally speaking, a faulty process can still yield positive results in the short term — and that’s what happened in this case (although the Cavs chose this “faulty” process as the lesser of many evils).
Fast forward to this year, and things are different. With Barnes gone and Kevin Durant taking his place, the Cavaliers will have to alter their their defensive strategy. But what the heck should Cleveland do?
The immediate inclination might be to give certain non-shooters the Harrison Barnes treatment, but the defensive strategy will have to be a little more nuanced than that (oh, and the Warriors don’t have a ton of “non-shooters”). As we saw in the Western Conference Finals, if the defense attempts to hide a big man on someone like Livingston or Iguodala, Golden State has an effective counter at their disposal. In these situations, the Warriors like to use these players as a ball screener for a shooter, forcing the defender (who usually wants to play zone in the middle of the lane) to leave the paint and stick with those guys.
A more accurate way of articulating a sound strategy against Golden State involves prioritizing options. This isn’t a new philosophy and you probably hear something to the tune of “we aren’t going to let him beat us” from a coach or a player all of the time.
For the Warriors, you try not to let Kevin Durant, Stephen Curry or Klay Thompson beat you. Now, you probably didn’t need me telling you that, but let’s discuss some of the math behind that notion.
Against Golden State, defenses must attempt to prevent shots with higher expected values, deter some of the lower-level options and then live with the results. In other words, giving “appropriate help,” as Jeff Van Gundy called it on a recent podcast with Zach Lowe. This might sound a bit theoretical, so I’ll use an example from Game 3 of the Western Conference Finals to demonstrate how, when and where these decisions come into play defensively.
On the picture below, you can see that multiple Spurs defenders have rotated over to David West to prevent his layup attempt. Although West’s 65.6 percent success rate on attempts within the restricted area this year might not be truly indicative of this potential shot (as he’s on the move and driving from the 3-point line), it still would have been a rather easy shot attempt and one with a substantially high expected value.
Once the Spurs clog the lane on West’s drive, there becomes three possible options as the Spurs begin to rotate — and here’s where the math comes into play. If Klay Thompson shoots about 45 percent on wide open shots from this spot on the floor (he shot 47.7 percent on wide open 3-point shots this season and 40.4 percent from the left wing), then the expected value of about 1.35 points per attempt becomes easily the worst of the three kickout options for San Antonio’s defense.
With that being said, watch how the possession plays out (and read some of my thoughts on specific rotations that would have been optimal in this situation).
Sure, it seems rather easy to make these decisions from afar with no time constraints rather than having to process them in the moment when split second decisions are needed. But c’mon, some of this is rather intuitive, even if the calculations take a little more time to complete. Instead of giving up a wide open 3-pointer to Klay Thompson in this situation, the hope is that the defense gives up a semi-contested 3-pointer to Draymond Green or a semi-contested midrange jumper to Andre Iguodala. That’s not really rocket science, folks. The hard part is actually doing it.
And here’s one last piece to consider regarding this play: When the defense is close enough to Thompson, they can force him to put the ball on the floor before shooting. This is a relatively uncomfortable task for Thompson, and it has been a solid defensive strategy this postseason.
Next: Nylon Calculus -- Measuring extra scoring opportunities
Ultimately, with Golden State even more equipped to win the championship this year, Cleveland will have to construct and execute an analytically sound gameplan to challenge the Warriors. If the Cavaliers aren’t meticulous in their approach to defensive rotations, the NBA Finals might just come down to Barnes’ replacement hitting shots — and that’s just what Golden State envisioned when signing Kevin Durant.
Source: NBA.com/Stats