What worked with the Celtics double big lineup and why they shouldn’t start it

In today’s modern NBA, playing a traditional lineup with a power forward and center is rare. Consider the case of Anthony Davis on the Lakers. His consistent hesitancy to play the 5 centers (pun intended) around not wanting to bang around with other bigs on defense and losing his advantage against smaller 4’s on offense.

In Boston’s first preseason game, Robert Williams started with Al Horford taking the baton off the bench. The two would never share the floor against the Magic. After head coach Ime Udoka talked about how well the double-big lineup of Williams and Horford was working in practice, it remained behind the curtain until the Celtics’ second exhibition game on Saturday night against the Raptors.

The numbers are promising. Conventional thinking would suggest that with two Through seventeen minutes (with Marcus Smart, Jayson Tatum, and Romeo Langford replacing Jaylen Brown), the duo registered a +10 together that unexpectedly included the Celtics shooting 11-for-18 from behind the arc and assisting on 13-of-16 made field goals.

The double big lineup has its inherent advantages, especially when the two big men are so diametrically different. Over the last few years, Horford has become one of those rare unicorn, a big man that can still battle in the paint and simultaneously stretch the floor with his three-point shot. Regardless of whether he’s playing next to Timelord or alone as the sole big on the floor, he’ll play more around the free throw line extended and pick-and-pop outside of the arc.

So far in training camp, he’s hit 5-for-8 from three, including all four against Toronto. “When I was here (before), even though I was shooting it, it was kinda new. My three-point shooting came in different ways than it does now. I really made sure that I worked on shooting off the pass quickly and not only off the pick-and-roll. Movement shooting, if I have to,” Horford said. “I do feel like I’m a much better shooter now than I was then, but that’s just the way the league has gone, so it’s forced me to work on that even more.”

And if he’s hitting that shot, that added floor spacing creates driving lanes for his teammates:

Scottie Barnes and Precious Achiuwa get crossmatched with Williams and Horford, so Horford wisely stays at the top of the arc to keep the rim-protecting Toronto center away from the rim so that Jayson Tatum has an open driving lane.

The biggest attraction for playing two big men though is utilizing mismatches against smaller defenders. On Saturday night, Horford was primarily defended by OG Anunoby (with Achiuwa covering Williams). On the first play of the game, they went right at that size advantage and put Big Al in the post.

Udoka has stressed getting his best offensive players to their best spots on the floor throughout training camp. Not counting his bizarro seasons in Philadelphia and Oklahoma City, Horford has been a steady threat on the block. In his final year in Boston, he ranked in the 65th-percentile in post. Udoka has said that when he was an assistant with the Sixers, they did not take advantage enough of Horford’s mismatches. It doesn’t sound like it’s something that they’ll really focus on as part of Boston’s offense, but if it’s there, they’ll take it.

It’s more likely that these post looks will look more like this. Off the inbounds, the Celtics run a zipper screen to get Fred VanVleet switch onto to Horford. Williams is keeping Achiuwa above the break, but as soon as the Raptors collapse, Horford can either hit Williams on the dive or Tatum for 3.

“That’s what’s going to make our team so dangerous. The fact is if we need to (play with double bigs), we’ll do that. If not, we’ll do the typical, what’s been going on now: four perimeter guys and one big type thing,” Horford said.

“With us, why I think it will work is because we all take the challenge. We guard the perimeter if we need to. With (Williams), I need to space the floor more. That’s what I have to do. He’s the kid of big that can pass the ball a little bit, when he rolls to the basket, he puts a lot of pressure on the rim. It opens stuff up on the perimeter.”

One of the subplots that could arise from starting the double big front court is the down stream effect on the rotation. Starting Williams and Horford most likely creates a necessary role for Enes Kanter as the backup center. That’s not necessarily a bad thing. His warts are evident, but blur your eyes a bit and he’s still a double-double in limited minutes. Against the Raptors, Kanter came in as the third big with either Tatum or Grant Williams manning the 4.

The more complicating issue is not necessarily who does play, but who doesn’t. The Celtics are wing-heavy, especially now that Romeo Langford has forced his way into the conversation. Coming off the bench, Dennis Schroder, Josh Richardson, Payton Pritchard, and Aaron Nesmith seem ticketed for playing time already. Adding Kanter to that mix makes 10. Udoka has said he’d like to 1) have a set starting lineup and 2) play 8-10 guys on a regular basis. That could leave at least two guys (and as many as three if you count Juancho Hernangomez who started in the first game) on the outside looking in.

Starting small seems like the more likely choice. If either Richardson, Nesmith, or even Langford slot in with the starters, then the second unit is the remaining two guys plus Schroder, Pritchard, and either Horford or Williams. Grant Williams becomes a matchup-based sub and it’s Hernangomez and Kanter behind the in-case-of-emergency glass.

Ultimately, it’s all about how the Celtics want to play. The buzz words out of Media Day and training camp practices have been “pace,” “sharing the ball,” and “0.5” (meaning players should pass, shoot, or drive in less than half a second). That sounds more small ball-y.

On one hand, these sound like rich people’s problems and really speak to the depth and versatility of the roster. On the other, the direction that Udoka chooses will go a long way in establishing the identity of this team and the future of the franchise moving forward. For the first time in years, it seems as though Danny Ainge’s investment and patience in five consecutive drafts is finally paying off. Everybody seems ready to contribute this season. It may seem like a minor decision — leaning on Kanter as a backup 5 vs. playing more of the young guys and going small — but it could be the guiding determination of how the rest of the year plays out.