And while the Nuggets recovered to win the game, the defensive switch nearly led to the second-biggest comeback of LeBron James lengthy playoff career. The past two seasons have produced the most efficient offense on record behind ever-growing numbers of 3-point shots.
“I think that the offense changed drastically, and the defense stayed pretty much the same for a while,” Toronto Raptors coach Nick Nurse said, “and now I think the defense is starting to have to adjust to such a different and drastic style of offensive play.” And now the zone defense, once disdained, has the potential to reshape this year's NBA Finals.
After peaking at 3% usage during the 2009-10 season, zone was used for just 638 plays in 2017-18, 0.2% of all possessions, according to Synergy Sports data. That was the culmination of six seasons of decline after zone defenses were more common in the NBA from 2009 through 2012, highlighted by the Dallas Mavericks zone helping them upset the heavily favored Big Three Miami Heat in the 2011 NBA Finals.
Seven years later, Miami played a key role in bringing the zone back in vogue. On Dec. 20, 2018, the Heat used a zone defense to slow down reigning MVP James Harden in a nationally televised win over the Houston Rockets.
Harden, who was amid a historic run of 32 consecutive games of scoring at least 30 points, went just 7-for-23 from the field against the unorthodox defense. Though Heat coach Erik Spectra dismissed the notion that there was any grand strategy behind turning to a zone a handful of games earlier -- “We did it because our man wasn't working,” he said -- other coaches took notice of how much zone Miami was playing.
“Teams have tinkered with zone rules and tinkered around the three-second rule for the middle man, so it's not your typical college 2-3 or 3-2 zone anymore,” said Detroit Pistons coach Diane Casey, who was the architect of the Mass' 2011 defense. Spectra has also changed where those players are by putting two athletic forwards on the perimeter in the Heat's 2-3 zones, with the team's smaller guards playing on the wings in the back line.
Snyder borrowed that innovation when Utah implemented a zone defense at midseason. “Having more length at the top, that player has an opportunity to impact the offense two different ways,” Snyder explained.
When the Mavericks used zone in the 2011 NBA Finals with Casey as their defensive coordinator, they were exposing a Miami weakness. At that point, before adding Shane Battier and unleashing Chris Bosh as a 3-point shooter, the Heat had a shortage of shooting.
Yet, there's a paradox to all these 3-pointers: In a counterintuitive twist, they've made controlling the area around the basket more important for opposition defenses. The Los Angeles Lakers defeated the Miami Heat 4-2 in the 2020 NBA Finals to claim their 17th championship.
Conversely, four of the top 10 (including Milwaukee and Toronto) were among the eight teams that allowed the most 3-point attempts. But zone defenses dramatically reduced shots in the restricted area, from 26% of attempts against man-to-man to just 16% against zone.
UNLIKE IN COLLEGE basketball, where legendary coaches such as Syracuse's Jim Botham and retired longtime Temple coach John Chaney built their defenses around exclusive use of 2-3 zones, NBA teams have found it more effective as a counterpunch. Overall, Second Spectrum tracking shows zone defenses giving up slightly more points per possession (1.12) than man-to-man defenses (1.11).
During last year's NBA Finals against an injury-depleted Golden State Warriors team, Nurse went to a zone defense typically seen in high school -- a box-and-one -- to thwart Warriors star Stephen Curry. He went back to it again during this year's Eastern Conference semifinals against Boston to try to slow down Emma Walker after he tore apart Toronto's defense early in the series.
After outlasting the Raptors, the Celtics have struggled against Miami's 2-3 zone in the conference finals. In a series in which the Heat's three wins have come by a combined 11 points, those possessions loom large.
Between players getting more and more creative with the ball in their hands, an influx of quality shooters at every position on the court, and rules being created and enforced to aid offense, defenses are left in a nearly impossible spot. “It's going to be hard for defense to trump offense like it used to in the late '90s,” former Philadelphia 76ers coach Brett Brown said earlier this year.
A couple of years ago, a zone defense, unless it was being played by the Dallas Mavericks, looked completely bizarre in an NBA game. According to Synergy play-type tracking, 18 of the 30 teams have played at least 100 possessions of zone through Thursday.
And a well-timed zone possession could be just what a defense needs to take the opponent out of its rhythm. “There’s a reason teams don’t run it all the time,” Warriors coach Steve Kerr said.
The Dallas Mavericks have been playing a healthy share of zone for several years now. When they won the championship nine years ago, the Mass played almost 800 possessions of zone in the regular season.
And this year, they’ve played almost twice as much zone (764 possessions, according to Synergy) as any other team. The game turned when Dallas went scoreless on its first five possessions (all against zone) of the fourth quarter, but that was with both Luka Ionic and Kris taps Mornings off the floor, and the Mass got some decent shots in that stretch.
The players at the top of the zone are high and active, running shooters off the 3-point line. The Toronto Raptors have played the second most possessions of zone this season.
And they’ve been slightly more successful with it (0.94 points allowed per possession, seventh in the league) than the Heat (0.97, 10th). Raptors coach Nick Nurse was asked about the personnel needed to be successful playing zone at a high volume.
According to Synergy, the champs have scored just 0.76 points per possession against zone, compared to 0.97 against man-to-man. In those situations, the coach of the offense has often drawn up a play to get an open shot.
Over the last several weeks, the same question was posed to some coaches and players: “If you come out of a timeout and the opposing defense is in zone, do you run the play that you drew up, or do you audible into a zone set?” If it’s a team that that does it sporadically, and they do it to take away your timeout, you’d like to have one that works against man and zone.
“The hard thing to convince NBA players is that, even if they are in a zone, still run the play that we called. Brett Brown, Mixers head coach: I want to run, by and large, the same thing.
It’s ‘Run the play, and this is what you’re going to be looking at if they’re in a zone.’ Because you can really scout and know if teams do that more than they don’t. Taylor Jenkins, Grizzlies head coach: “Obviously, when it’s thrown out as a surprise, I try to get the guys to just execute the play.
Brooklyn played just five possessions of zone against Miami last week, probably because the Heat got into the teeth of the defense so easily… When you have a brilliant passer who’s 7-feet tall, putting him in the middle of the zone seems like a good formula for success.
The one occurrence of illegal defense in the NBA that I know about is the “3 seconds in the key” rule. If you're on defense and aren't aggressively guarding someone, you can't spend more than 3 seconds in the key at a time.
Zone defense- a defensive strategy where everyone guards an area instead of a player. In basketball, the two types of defense a team mostly plays are called man-to-man and zone.