CelticsBlog film study: Celtics break out zone defense against 76ers

At shootaround before the 76ers game, head coach Ime Udoka stressed the importance of preparedness and game planning, from the coaching staff down to the players. Over three weeks ago, the Celtics had coughed up a seven-point late fourth quarter lead to Philadelphia on the back of Joel Embiid’s 41 points, including 17 in the final frame. Boston was admittedly without Al Horford and Robert Williams, but against an MVP-caliber player capable of an MVP-caliber performance, Udoka wanted to be ready.

The Sixers raced out to a 32-14 advantage after the first quarter. Some of that was due to eight turnovers. Some of that was a strong start from Embiid with eight points.

Doc Rivers has built so much of Philly’s offense around shooters and playmakers coming off of Embiid screens above the break. The 76ers are in the 93rd percentile in generating points from pick-and-roll ball handers. With the big man’s ability to play in the short roll or in the pop and Seth Curry and Tobias Harris able to score in the mid-range, opposing teams have to pick their poison.

To change the dynamic of the game, Udoka switched the Celtics’ defensive scheme and went almost exclusively to a zone defense for twenty straight minutes in an attempt to stay within striking distance. Subsequently, from midway through the second quarter until the end of the third, Boston outscored Philadelphia 39-37, in large part due to their change in defense. Philadelphia takes the 4th fewest three-pointers per game — and this is without Ben Simmons — so Udoka wanted to push them out of their comfort zone. On Friday night, half of the 76ers’ shot attempts in that span were from behind the arc and they only hit four of their 16 three-pointers.

The strength of Philly’s wings is their length defensively. We saw that manifest itself in twenty Celtics turnovers with Jaylen Brown and Jayson Tatum combining for 12. However, they’re not great shooters. Tobias Harris is shooting his worst percentage from behind the arc in ten years (29.9%). Matisse Thybulle has always been jump shot challenged; he’s at Marcus Smart levels at 28.6% from 3.

Playing a 2-3 or 2-1-2 zone, the intent is to keep the 76ers out of the paint and on the perimeter. If the defense is playing on a strong, it can eliminate driving lanes with defenders guarding space rather than a player.

Unfortunately for the Celtics, Embiid is a fantastic zone buster. If he gets the ball at the free throw line, he shoots above league average in the mid-range and for a big man, that’s pretty good. It’s a shot that Boston will likely live with though, especially with Robert Williams challenging him fifteen feet away from the rim.

But even in a zone, Embiid is a load to deal with. As the clip starts, you can see Dennis Schroder cheating a bit, trying to chip the bigger Embiid, and maybe prevent an entry pass. That split second misstep gets the ball in rotation and Thybulle an open corner 3. Again, that’s the poison the Celtics were willing to swallow. Unfortunately, Philadelphia closed hitting 6-of-9 from 3 during a critical stretch in the fourth quarter and there’s only so much you can stomach.