Talking zone defense, NBA big men ... and the trade market for NBA big men

All via The Jake Fischer Latest

Remember when we wrote all about how the NBA has become supersized?

That Halloween story included a prediction echoed by several coaches: This season, they forecasted, was destined to feature a marked increase in zone defense across the league.

And they were right.

According to Second Spectrum data provided to The Stein Line, NBA teams were employing zone schemes on 3.6% of possessions leaguewide in this 2025-26 campaign through Monday's games. At first blush that probably reads as a miniscule amount, but it's a monster increase — 12 times' worth — from the 0.3% clip witnessed during the 2017-18 season.

It's been a steady climb over time and we are seeing more and more zone when teams emerge from timeouts and look to counter the play drawn by the other team that was presumably conceived with a man-to-man defense in mind.

Some around the league also believe that those numbers might actually be higher for zone possessions than the available numbers suggest, since it's difficult for the tracking software employed to identify possessions where teams switch mid-possession from zone to man or vice versa.

To name one extreme example of the rise in zoning: Those jumbo Houston Rockets, who often deploy All-Star center Alperen Şengün next to either Steven Adams or Clint Capela, are being lined up in zone structures by Ime Udoka on a league-high 18.4% of their defensive possessions.

That's nearly twice as often as the third-ranked Nuggets, with Denver going zone under first-year head coach David Adelman at a rate of 9.9% of its defensive possessions ... and 16% of the time that Jonas Valančiūnas is on the floor. Milwaukee is currently No. 2 on the zone charts, settling into that alignment on 14% of its possessions ... and 9% of the time that Giannis Antetokounmpo is on the floor.

You'll note that the teams that rely most on zones, furthermore, all happen to be some of the league's hugest.

So what does this all mean?

"I think it's just playing different ways," said Celtics coach Joe Mazzulla. "Obviously players are getting so much better. The game is always tilted towards the offense, so you're always trying to find different ways to impact the games defensively."

I think it could be yet another indicator, too, that the big man is alive and well in the NBA after all that misguided talk of true size going out of style.

Consider that a strong signal — if my read is right — that we're going to see some significant center movement on the trade market in coming weeks.