Brad Stevens continues to experiment with lineups as Celtics steal home court advantage from Bucks

Brad Stevens entered the NBA as an open book. He dove into the intricacies of his schemes and game plans and learned to keep things close to the vest through six seasons — he staved off a question the collapses on Giannis Antetokounmpo on Sunday — his tendencies remain or better yet, lack of tendencies. Five games into the playoffs, he continued to mix and match lineups and returned veteran Marcus Morris to the starting lineup in a surprise move.

Like in past playoffs, Stevens utilized his entire roster to craft a 10-man rotation in the victory of the Bucks. Even Daniel Theis got run against an Antekounmpo-led group after Aron Baynes left with an ankle sprain, and the C’s came out on top by four points in those minutes behind a pair of threes from Terry Rozier and Gordon Hayward.

Danny Ainge once said these Celtics can almost afford an injury with their depth. The loss of Marcus Smart then blew a hole in the starting lineup that drove Boston’s rise in the East following a 10-10 start to the season.

Stevens since crafted two new starting lineups, starting Aron Baynes against the Pacers, and now Morris vs. Milwaukee. That latter group posted a +38.6 net rating in 12 minutes, allowing Gordon Hayward to rotate off the bench for secondary ball-handling.

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Kyrie Irving called the mixing and matching entertaining.

“I think that obviously it adds spacing. But there’s still a toughness that (Morris) and Baynes bring, either one, coming off of our starting unit. Obviously Smart is not here, but throwing either one of them in there works for us, and we’re going to make it work especially when we want to go at specific matchups. I think it worked to our advantage.”

Morris shot 4-for-6 to rack up nine points and blocked three shots as part of the wall that the Celtics’ interior formed to keep Antetokounmpo off the baseline. Morris grabbed seven rebounds and the Celtics outscored the Bucks by 18 when he was on the floor, the second highest +/- aside from Irving.

The insertion — against Brook Lopez and Antetokounmpo — allowed Boston to scram-switch on mismatches. Al Horford and Morris could both guard Lopez and Antetokounmpo in rotation, so long as Lopez didn’t attempt any post-ups with a size advantage on Morris.

Lopez hung on the perimeter, as Stevens gambled he would, and only scored three points. He got good looks at the start of the fourth quarter and barely missed a three-point attempt before traveling after a successful up-fake on Horford.

The real multiplier paid out to Stevens came from Morris’ playmaking. Morris dished a perfect pass to Rozier for a corner three and, instead of attacking head-on through Antetokounmpo during another drive, dumped for an easy look.

Out of Stevens’ 12 most-used lineups in the playoffs so far, 10 posted positive net ratings. That followed a regular season where only two of his most-prominent rotations that did not feature Smart went positive.

In 41 minutes, the Horford-Baynes pairing with the starters posted a -3.5 net rating, though with a 101 defensive rating. Hayward, alongside Irving and Rozier, posted both Boston’s most impressive offensive and defensive ratings in over a 20-minute sample size.

Rozier’s resurgence in an on-ball role offensively with renewed defensive energy played a key role as well in getting Irving going off the ball. Rozier shot 4-for-8 off the bench with nine rebounds against Milwaukee. Alongside Irving, Horford, Jaylen Brown and Jayson Tatum, he worked a 0 defensive rating through seven minutes in two separate games.

The sample sizes here are not nearly large enough to draw from following a sweep and one second-round game. They are proof of three things though. Stevens is not cutting his rotations down. The Celtics can court positive groupings without Smart. Small-ball — albeit with Hayward off the bench — can work to start and finish games. We saw that in Round 1 most prominently, when the original small-ball lineup that started the season closed a game.

“I think Marcus’ size and yet the skill and ability to play in a smaller fashion made the most sense. I also wanted to keep Gordon coming off the bench so we could play through some of his actions when those other guys went to the bench,” Stevens said. “We’ll see how it looks when we go back and look at it on film, but obviously I thought it was good.”