The 2-3 zone is one of the most popular defensive looks in the college ranks, yet it’s not often seen at the NBA level. The league’s defensive 3-second rule (bigs can't stay parked in the paint unless they are guarding someone there) makes it a bit of a challenge to pull off during the pro ranks, as do more talented playmakers and shooters.
Still, the 2-3 zone remains in some teams’ bag of tricks. The Heat went to it with some success earlier this year against the Celtics in a road win at the Garden. The Mavericks famously used it at various points against LeBron James and the Heat during the 2012 NBA Finals to help them pull off the upset. No team runs it all game long, but situationally, it can be a valuable tool.
Brad Stevens hasn’t used a ton of zone during his time in Boston, especially in the last couple of years. He has mixed it in for some inbounds situations (to mess up an opposing team’s play call) but the Celtics have largely played a disciplined man-to-man scheme, full of switching and help rotations.
However, Stevens' previous defensive plans have been dealt a bit of a tough hand the past few weeks. His backcourt has been decimated by injuries, while arguably his best big man defender (Daniel Theis) is down for the year. Not only has this left Stevens without a number of key defenders (Marcus Smart, Theis, Gordon Hayward), but it has also limited the versatility of his roster. The guard depth chart over the past couple weeks has consisted of Terry Rozier, Shane Larkin, Jaylen Brown and a number of G-League players (Xavier Silas, Jabari Bird, Kadeem Allen). Allen and Bird have proven to be capable defenders in short stints, but their limited offensive skill sets make it tough for the Celtics to get away with enough scoring options and spacing when they’re on the floor.
With limited options to pick from, Stevens has had to dig deep into his playbook over the past couple games to keep the C’s six-game win streak going despite a laundry list of injuries. In doing so, he has found a valuable option for this group to get stops in spite of their limitations: A 2-3 zone.
In wins against the Raptors and Jazz, Stevens has used a 2-3 zone with various lineups with a great deal of success. Boston broke open a 94-94 game against the Raptors midway through the fourth quarter with a 10-0 run once Stevens went zone, which led to a 110-99 win. The Celtics also clawed their way back into the game against the Jazz in the second half on Wednesday night (despite missing Horford and Morris) with a steady diet of zone mixed in. Stevens went with a 2-3 defensive look in the final two minutes, which produced a 7-0 Celtics run on the way to the 97-94 win.
"We played more zone tonight than we did in the past two years," Stevens said after the game.
So what exactly is working with this zone? And will we see more of it going forward? After reviewing the tape it’s easier to see a few things that Stevens likes about it with his personnel and how it could become a regular staple of this team's defensive gameplans for the postseason. Let's examine a few noteworthy developments it has produced over the past couple games.
1) A way to hide Greg Monroe: The 6-foot-11 big man has been a vital offensive contributor for the Celtics, averaging 18.9 points per 36 minutes over his 20 games in green. He has one of the best post games in the league and is a monster on the offensive glass, which leads to plenty of open putbacks. The Celtics have been in dire need of easy buckets like this all year long, but it usually comes at the expense of their defense when Monroe is out there. Teams can attack him in the pick-and-roll and have usually done it with success.
While Monroe’s defense has shown progress on various nights, the 2-3 zone has allowed the C’s to park the big man in the middle with some support. He doesn’t have to close out on shooters and has backline help when trying to defend the pick-and-roll. Notice how he holds his own against Donovan Mitchell in these plays.
Next possession, Mitchell takes one extra dribble in the in-between on the PnR... allowing Brown to dig down and steal the ball. Ingles and Rubio both open here... eyes out! pic.twitter.com/7LddPdmRtS
— Andy Larsen (@andyblarsen) March 29, 2018
Next play, Mitchell still sees the help, but this time takes this floater... Crowder's wide open. It's just a really tough shot. pic.twitter.com/IXdur3sUAT
— Andy Larsen (@andyblarsen) March 29, 2018