Celtics defense looks rusty in first scrimmage vs. Thunder

It may not have been pretty, but basketball is back.

The Boston Celtics lost 98-84 to the Oklahoma City Thunder in their first live-action scrimmage inside the bubble. If listeners of the broadcast took one thing away from analyst Brian Scalabrine, it’s that this is a very, very good Thunder team.

The results are devoid of meaning, as is a complete deep dive into how each individual performed. Overreactions are just too easy, and no game is more insignificant to such a task than the first. Such an idea is compounded when the true rotation players only get minutes in the first half.

Instead, let’s think about what we can gain from a setting like this. We should be more concerned with defensive rotations and the crispness of reads in the offense than whether they make shots. Going 3-for-14 in the first half isn’t worth panic, nor really addressing.

What was revealing was Stevens’ desire to keep the rotations fairly similar to how they were early in the season. He clearly values the chemistry between their prime eight (the Smart-Brown-Hayward-Tatum-Theis group with Kanter, Wanamaker, and Ojeleye off the bench) over trying to inculcate younger pieces and see if they mesh within this group. His substitution patterns in those first twenty minutes mirrored that of a regular game without Kemba Walker.

Despite the continuity and previously-developed cohesion, the Celtics looked pretty loose on the defensive end. Oklahoma City, featuring multiple attacking guards like Chris Paul and Shai Gilgeous-Alexander, made it a point to attack Boston through ball screens and met little resistance.

Whenever the Celtics play Daniel Theis at the 5, they have an objective: do not switch Theis onto the perimeter. He’s not a complete disaster there by any means and probably their most mobile center until Robert Williams gets more run, but the natural mismatches that occur are something they’d like to avoid.

Theis’ job is to avoid getting himself into positions where savvy guards can take him away from his assignment and forced into a mismatch. But Paul, one of the most cerebral point guards ever, was a little more savvy on Friday night.

Theis was caught in no man’s land; he was too low to be impactful at getting the ball aggressively out of Paul’s hands, but too high to be considered in true drop coverage. His angles were a little too high, allowing the Thunder to force the switch.

Not every team has a point guard with the maestro playmaking of Paul, particularly in the Eastern Conference. A second round series with the Raptors and the Kyle Lowry-Marc Gasol pick and roll tandem could pose a problem in the playoffs though, particularly considering the Celtics will want to extend their defense beyond the 3-point line to pick up the sniping Lowry. The point is, Boston needs to come up with a solution for that in-between game to protect Theis.

Photo by David Sherman/NBAE via Getty Images

There was an entire other half of basketball after the starters untied their sneakers. We got to see some of the hyped youngsters like Tremont Waters and Robert Williams, both of whom had flashes of success. Waters finished with 7 points and 5 assists in 16 minutes.

Stevens clearly designed this scrimmage around the first 20 minutes, giving leeway for the core group to work themselves into shape together. The second 20 saw the youngsters do battle on their own in a lineup completely lacking spacing. The Celtics’ bench only made three treys, and Carsen Edwards looked a tad off.

That said, there was one after timeout (ATO) play from Stevens that caught my eye for Edwards. As a counter to their normal motion, Edwards was sent backdoor cutting from the wing to the hoop. He quickly reversed course, darting back to the corner off a Kanter screen:

Part of the responsibility here is on guys like Jaylen Brown or other perimeter defenders to get back around the screen to reclaim their assignment. By struggling at the point of contact, Brown et al can leave Theis out to dry, meaning he has to switch. Ball screen defense is all about communication, angles, and dependability. Teammates have to know the guy next to them is in the right place. It may take a few games to get back to expectations on this front.

When Theis is not in the game, the same thing goes for Enes Kanter. While Kanter isn’t going to receive Defensive Player of the Year votes any time soon, he at least needs to stick to and execute the coverages. The perfect foil for Kanter: a pick-and-pop 5 with the second unit.

Enter Mike Muscala for the Thunder. Oklahoma City trotted him out with both Paul and Dennis Schroder, running constant ball screens. They started with an empty-corner pick-and-pop, getting Muscala a wide open three, which he knocked down.

Guys will make shots. I’ve yet to see a shutout in my years of watching. What Kanter cannot do though is let the shooting of his opponents get into his head to the point where he worries too much about his guy and not execute coverages. He can’t give up layups under any circumstance:

Kanter will play a sturdy 14-to-20 minutes a night in the playoffs, and Stevens’ predictable substitution patterns serve as a bullseye for opponents to focus on. The recent change of the Philadelphia 76ers starting lineup has moved Al Horford to the backup 5, where his minutes as a stretch-5 will coincide more frequently with Kanter’s. Toronto has Serge Ibaka, a 39.8 percent 3-point shooter, anchoring their bench mob. Kanter has to figure out the pick-and-pop before the post-season arrives.

Whether as a change of pace or a legitimate strategy he sought to test, Stevens played several possessions of a 3-2 zone, too. That formation didn’t have much success against the Thunder ball screen actions either:

Boston’s overall defensive performance can be characterized as “bleh.” They gave up a ton of layups in man or zone, and were torched by Steven Adams on the offensive glass. Boston’s perimeter defenders didn’t contain the Thunder guards, putting too much pressure on Theis to step up and try to contest shots. Adams would clean up the mess and got far too many easy looks.

It wasn’t all negative for the first unit on defense. Jayson Tatum had some impressive flashes on D even though his shot wasn’t falling. If he becomes a reliable, high effort defender who cares about every closeout like he does this one, it could help cover up the burdens heaped upon Theis to clean up the mess:

I’m not one to look at preseason games and think there’s a ton of substance here for how the Celtics will perform. But there are clues about what areas they need to continue to give TLC to if they are to go chasing waterfalls. With a little time in the film room and on the practice floor dedicated to tightening their ball screen defense, these issues certainly won’t creep up on them again.