CelticsBlog film study: Philly’s defensive wings vs. Boston’s versatile wings and making Embiid defend the pick-and-roll

Despite losing three of four regular season meetings to the Philadelphia 76ers, Boston Celtics fans should not fret. This Sixers team is much different now. First off, they were 29-2 in games in Philadelphia, something that won’t factor into a postseason series. They’re without Ben Simmons, who is out after suffering a subluxation of his knee. Without him, a big part of their mismatch ability on both ends is gone.

However, the Sixers are a formidable #6 seed, talented with starters and strong in the identity of their second unit. Whether inside the bubble, on the road or in the City of Brotherly Love, the Sixers have a consistently strong defense, ranking 8th in defensive efficiency and featuring a formidable anchor in the interior, Joel Embiid. They’ve defended the Celtics fairly well and are not afraid to use their great length top to bottom.

How can the Celtics attack them in a playoff series? What are the areas the Sixers are likely to be aggressive in and what pressure points have they had success with in the past?

A large part of those questions remain somewhat unanswered, as the teams never met at full strength and with the impending absence of Simmons. But the context of how the Sixers defended Boston’s offense throughout the four meetings can illuminate the best points of attack for the guys in green.

The Celtics’ base offense has been a 4-around-1 continuity, triggered by the big man (usually Daniel Theis) flashing to the top of the key. There are so many options around Theis when the ball is in his hands. The Celtics have three 20-point scorers that can be on the floor at one time, and with a variety of screens, handoffs, or cuts, the defense can be compromised as soon as the ball gets into Theis’ hands.

That may be why the Sixers have, for small stretches, denied reversals to get Theis the ball and prevented the big man from getting open. Whether he’s at the 5 or someone else is, the Sixers see this as a pressure point worth pushing:

Theis is a smart player, and the Celtics have a ton of counters to cope with it. That said, the counters make Boston a little easier to guard.

Brad Stevens would defer to more deliberate offense out of their Stack formation, where two players would start at the free throw line and pop to the middle-third of the floor to get open. It’s a common action the Celtics have been running all year, but indicates their willingness to avoid leaving Theis stranded on an island:

One of the advantages of relying on this entry to offense is that the Celtics can put all three of their versatile wings--Jaylen Brown, Jayson Tatum, and Gordon Hayward--into the two-man stack. The offense naturally runs through one of them when they screen for each other while also being less prone to interruption.

The biggest benefit, though, is the removal of Embiid’s defensive impact from the ball screen and thus, making him less of an impact in the middle of the floor. Stevens will put Brown and Tatum in the stack, relegating Theis to the corner, taking Embiid with him. Otherwise Embiid would help at the rim and block shots whenever the Celtics attack the restricted area.

Stevens would rather put Semi Ojeleye in the stack and trust him as a playmaker off the short roll than challenge Embiid at the rim:

Getting Embiid into foul trouble is paramount, as the Sixers lose a great deal of offensive firepower if he’s forced out of a game. He got in foul trouble in Boston’s lone win this year.

A balance needs to be struck between attacking Embiid in the pick-and-roll and finding other ways to naturally go at him. If the Celtics try to go at him through ball screens, that may be a battle they lose more than they win.

The Sixers consistently deploy drop coverage when he’s in, keeping their rim protector within his comfort zone. He’s a tremendous shot blocker, has great patience to let plays come to him and covers a ton of ground.

However, there are plenty of ways Boston can, and should, go at him through ball screens. Some are more nuanced than others, and most work no matter who is at the 5.

Three, in particular, stand out, and are the subject of this week’s Film Room topic:

We haven’t mentioned the most common way to thwart drop coverage across the league: the pick-and-pop. Theis is solid here, but the Celtics have proven throughout the season they won’t settle for that as a long-term strategy. Stevens would rather come up with counters that keep the ball moving and in the hands of their best scorers.

The Sixers could force their hand. I’m not sure where things stand heading into the playoffs with the minutes at the backup center. Robert Williams has played well of late. Enes Kanter is the veteran presence who can best guard Embiid one-on-one. Grant Williams gives an element of speed and shooting and could be an intriguing option.

One thing that’s certain is that as soon as Theis checks out, the Sixers can sag off the Celtics’ bigs atop the key. The other four defenders clamp down and deny passing options, trying to encourage Kanter and others to make plays one-on-one.

The results haven’t been great for the Celtics:

On the wings, the Sixers have a ton of length. Tobias Harris, Josh Richardson, Matisse Thybulle and even Shake Milton have strong standing reach and can be strong impact defenders as a result. The Sixers will vary their pressure based on the actions the Celtics run and the lineups they face. But with length and athleticism Boston has, they should be able to handle the added pressure.

As good as those Sixers’ defenders are on the wings, they try to switch “likes.” or players whose assignments are roughly interchangeable. But the design of Boston’s offense leaves ample room to attack those switches through slips, and quick-occurring two-man actions that create communication breakdowns.

Through the flow of that base motion, the Celtics had success in catching the Sixers’ napping and over-anticipating, leading to open threes:

Boston’s success against switches gives the Sixers more reason to try a more disruptive and physical tactic against the Celtics’ versatility on the wings. As mentioned, they can deny Theis the ball at the point of attack, but they can also dial up their activity on the perimeter.

When Philly does go over ball screens or try to fight their way back into plays, the Sixers’ wing defenders have some of the most active hands I’ve seen. They aren’t afraid to poke those arms at the ball and create deflections or back-tips. It can be frustrating and create a lot of turnovers:

There’s still a lot we don’t know about the rotations that will get answered during the first few games of the series. Will the Sixers play Al Horford and Embiid together for long stretches now that Simmons is out? If so, who will Horford guard? (In the past, it’s been Jaylen Brown). Do Kyle O’Quinn or Norvel Pelle get any minutes at the 5? Does Brad Stevens go with Enes Kanter to wrestle with Embiid in the paint or continue using Robert Williams as a vertical threat?

Philly is banged up, and the Celtics are playing their best, most unselfish ball of the season at the right time. Things are trending in the right direction for the gang in green, but this is no walk in the park. With smart pressure on the wings and disrupting the flow of Boston’s base motion, the Sixers have ways to get under the Celtics’ skin.