NBA: Boston Celtics at New York Knicks
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Communication, precision are key when switching screens

New coaches bring change — that’s often why they’re hired. Ime Udoka has started with some big tweaks on the defensive end. Mainly, emphasizing switching on a higher degree than before.

In theory, the Celtics have the right personnel to be very switch-heavy. Jayson Tatum, Jaylen Brown, Marcus Smart, Josh Richardson and Grant Williams are all multi-positional defenders. Al Horford is a master of angles and Robert Williams is quick enough to keep others in front.

In practice, getting comfortable in a new system with such an unorthodox form of defense means bumps in the road. One of those potholes tripped up the Celtics on Opening Night in their double overtime loss to the New York Knicks. CelticsBlog’s Adam Taylor did a fantastic write-up on the defensive breakdowns that ultimately cost them the game.

Within Udoka’s postgame presser, he mentioned the in-game adjustments that may have been a source of the Led Zeppelin-style communication breakdowns:

“We switched from switching everything to switching 1-through-4, and guys got a little confused and went under a little bit expecting Rob to switch out. Changing our coverages in the fourth quarter and overtime, we wanted to keep Rob on Julius Randle. And some of our guys just messed up the coverage, we got to be more communicative, we switched it up late in the game, and I know we made a few mistakes that kept them in the first overtime for sure.”

Anything that changes on the fly in-game is bound to be a risk. Udoka felt the reward (keeping Williams on Randle) was worth those risks. The decision wasn’t flawed, but the execution of his adjustment shows just how difficult switching can be.

Boston Celtics v New York Knicks
Photo by Nathaniel S. Butler/NBAE via Getty Images

From a teaching perspective, switching was always explained and summarized by the “three T’s” — talk, touch, and take. The first step is to communicate, for both teammates to recognize that two opponents are converging and a switch is about to take place. For the most part, that communication needs to be loud (to be heard in an arena such as Madison Square Garden), early (before the offensive players converge so maximum preparation can take place) and continuous (don’t just say “switch” once — keep talking so there’s little chance of not being heard).

After the communication, both defensive players must “touch.” While NBA-caliber length and the precision of angles lessens the necessity of physical contact, the sentiment remains. If two defenders aren’t close enough to touch each other when switching, the offense can exploit them in numerous ways: slips, keepers, pull-up shots with no contests and other miscommunications. Often, a tag is a great physical way to acknowledge when the switch takes place while preventing those offensive avenues from emerging.

Finally, the “take” occurs when the assignment has officially been handed off from one defender to another. The man accepting the ball handler takes over the responsibilities of keeping dribble penetration out of the lane. The guy who passes off that responsibility must now jump to inside position on his man, which usually means going underneath his defender to prevent a dive to the rim from having any impact (we’ll come back to why that’s so important later).

It may sound simple or black-and-white, but the grey area comes within the complexities of an NBA defense. There are times when the Celtics will try not to switch. Often, Udoka will want to preserve certain matchups, keeping a guy like Marcus Smart on the opponent’s best player in crunch time. As we saw in Madison Square Garden, the Celtics want to keep their matchup solid at the 5, only switching 1 thru 4. Sometimes there will be specific plays or actions in the scouting report that are simply too hard to switch.

In any instance, the saving grace for a defense is always communication. When Timelord is involved in a screen or handoff, he has to be the one instructing his teammates not to switch and to play the action differently. His voice has to be the loudest, and his recognition sharpest, in order to save the Celtics the headaches of deciphering on the fly who to switch and when. Processing slows down reaction times, and no defense is effective when they’re a half-step slower than their adversary.

Part of Udoka’s mission during film sessions and practices is to identify the areas where these breakdowns occur most frequently. When they find the themes between their errors, they can address them. Against the Knicks on Wednesday, the most egregious switching errors took place late in the game, and against one simple action: dribble handoffs.

Handoffs are like ball screens on a fast track, and they’re much different for the defense even if the action creates similar results for the offense. Think about it from the perspective of Robert Williams, a big man who guards the screener in pick-and-roll situations most frequently. When a pick is being set, Williams is a help defender, seeing the entire floor with his peripheral vision and, most importantly, not guarding the ball. It’s much easier for him to recognize and call out a screen that’s about to arrive because he has no worries about getting scored on or beat with the ball at that exact moment.

Handoffs, however, are a different breed. When guarding a driving, physical big like Julius Randle, Williams has to be focused first and foremost on playing the ball. Take good angles, don’t overextend pressure, and most importantly, don’t take his eye off the ball. It’s so hard to simultaneously watch Randle (a dangerous driver and isolation creator) while anticipating the handoff is about to arrive.

We saw how that breakdown can cost the Celtics on Wednesday. Below, Jayson Tatum is caught slightly off-guard about the switch, as he doesn’t process quickly enough that Williams is the man he’ll be engaging with. Tatum, guarding Evan Fournier, plays these handoffs like he’s going to switch. He almost goes under the handoff, a sign of the “take” responsibility where Tatum assumes he’s now taking Randle and jumping low for inside position.

The issue: Williams isn’t supposed to switch with him. The lack of early communication creates confusion, and the result is a bona fide shooting threat getting open look after open look in overtime:

At the very end of the clip, you can see Tatum lamenting over the coverage, expressing his expectation that Williams would show higher. Smart, across the floor, helps try to explain to Tatum the difference in coverage.

The same thing happened a few possessions later in overtime with Jaylen Brown. Same mix up, same confusion and dissent among the Celtics on-court after the fact:

Here’s a much-needed reminder for all the couchside coaches at home: NBA basketball is freaking hard. TV viewers have the benefit of aerial views to see all ten players on the court. In the moment, these guys can only see one or two. They’re relying on each other to call out actions, process them quickly and react in the exact ways that don’t yield an advantage, all while competing with nearly 20,000 screaming fans.

Udoka has brought with him some new tendencies and tweaks to the old scheme. That’ll require a little bit of patience and, unfortunately, some growing pains in crunch time moments. There’s no better teacher than failure.

The Celtics will tighten the screws on their defense and find ways to solve some of their communication or switching woes. We’re one game in, and these mistakes are bound to happen this early in the season. At the very least, an early introduction to these challenges gives everyone involved plenty of time to search for solutions.

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