Acommon misconception about today's NBA is that as teams and players have mastered the art of efficient scoring, defense has come to matter less. The reality is the exact opposite: The evolution of offense has made defense more important than ever. Coaching staffs and players have to work that much harder, and be that much more creative, in order to keep pace.
In the face of offensive advancement, one of the most important defensive counters sweeping the league is cross-matching, especially with centers. Because of the difficulty of guarding modern pick-and-rolls, the increasing skill level of big men, and the way offenses increasingly orient their schemes around those skills, defenses are seeking ways to keep their own centers in optimal help position and out of compromising actions.
If there's a remotely shaky or hesitant shooter on the floor, or even just a low-usage perimeter player who isn't usually involved in the offense, a center is likely to nominally "guard" that player (no matter what size he is) at some point in a game, while a wing-sized player slides up to defend the opposing five.
Rejiggering matchups in that fashion has two significant benefits for defenses: One, their best rim-protectors can hover around the basket rather than constantly getting drawn into high ball-screen action or having to account for stretchy bigs on the perimeter. And two, opponents' 1-5 pick-and-rolls become a lot more switchable - not just because wings typically have a better survival rate than bigs when marooned on an island against guards, but because those wings have their center behind them, ready to provide cover at the rim even if they get burned on the switch.
Most teams deploy that tactic in select situations and matchups, but some - like the Boston Celtics, Charlotte Hornets, and Houston Rockets - use it as part of their base defense. And those teams' coaches all branch from the same tree: Ime Udoka started cross-matching his centers regularly during his lone season as the Celtics' bench boss, and now he's doing the same thing with Alperen Sengun in Houston. Joe Mazzulla, Udoka's assistant turned successor, has taken the baton and run with it in Boston. And Mazzulla's former lead assistant, Charles Lee, has done the same thing as a first-year head coach in Charlotte.
Those tactics are partly why the Rockets rank fourth in defensive efficiency even though Sengun is vulnerable in certain ball-screen coverages and offers below-average rim-protection for a center. The Celtics rode their defensive formula to a championship last year and are once again a top-five unit this season. Even the Hornets, one of the worst teams in the league, have been halfway respectable on defense, ranking 18th. All three teams are in the top 10 when it comes to defending the rim.
"I think offensive guys are too good to see the same thing, (even in) one game, let alone throughout the season," Udoka said. "So you try to keep them off balance. But also it's a necessity for us to use our guys and play to their strengths. We've got a rim-protector that's a little bit different; we try to work around that and switch as much as we can to take away certain things, like we did in Boston with Al Horford and Rob (Williams III) playing off the ball. And Alperen's really starting to understand what we want him to do as far as roaming and being a rim-protector."
The Rockets allow 4.6 fewer points per 100 possessions and their opponents shoot 4.2 percentage points worse at the basket with Sengun on the floor, per Cleaning the Glass. He was one of the most improved defenders in the league last season, and playing a free-safety role more often has helped elevate him another tier this season.
"Even before the NBA, I was just really good at help defense - blocking shots, stopping the ball," Sengun said. "Ime just saw that in me and let me show it. ... We started (cross-matching) a bit last year. Couple games he was trying it with me, and it was working. So this year is, like, much more of that. He wants me to be on the help side."
Udoka's had Sengun spend entire games as the primary defender against off-ball guards who are low-volume 3-point shooters, like the LA Clippers' Kris Dunn and the New York Knicks' Josh Hart. That can pose individual challenges for Sengun when those quicker players handle the ball and try to attack him in space, but it serves the aims of Houston's defense as a whole.
"I feel like when I'm guarding the those guys, we change their game plan, you know?" Sengun said. "Like, Kris Dunn is usually not bringing the ball up, but when I'm guarding him, he's bringing the ball up. That's not how they want to play, right? Or we're forcing (a non-shooter) to shoot, and if he makes it, he makes it. We're taking that."
On the other end of the positional spectrum is Jrue Holiday, the Celtics' nominal point guard, who occupies a unique place in this tactical movement. He spends ample time guarding big men in Boston's matchup-scrambling defensive scheme, and he's also increasingly guarded by roving bigs at the offensive end - not because he's a bad shooter, but because opponents are searching for any viable help point when facing Boston's five-out attack.
"For me, it's probably more weird having a five guard me (than the other way around). That's never happened before," Holiday said. "Being that wide-open and getting a rhythm like that is - I mean, I enjoy it. But I do see the aspect of, if you're missing threes ...
"But there's so many different ways, especially as a guard, that you can combat that if you're not making shots. There's ways to get the whole team in rhythm, rather than just bringing it to me solely all the time. For us, it's a lot of pitches to screen-and-roll to get the ball in the pocket, you can drive the dribble-handoff - just making it confusing for a big, not knowing how to play with my speed."
As Holiday notes, there are obvious counters to cross-matches, including guards setting ball screens and then utilizing their driving and playmaking skills on the short roll. But to Sengun's point, many defenses are happy just to force offenses that can otherwise hum in their sleep to deviate from their usual approach.
"We (practice for it) all the time," Holiday said. "Last year against Denver, (Nikola) Jokic was on me a bit, and I think we figured that he would be. So there are things that we do in shootaround ... where we've gotta figure out if we want to put the five in (the action), or if we want to take him away from the basket, where do I go and what do I do?"
The Dallas Mavericks, whom the Celtics beat in last year's Finals, also love to cross-match, which allows them to unleash wily second-year center Dereck Lively II as a back-line rover. (Their scheme often resembles a one-man zone where he isn't guarding a specific player but is just responsible for the weak-side corner and dunker spot, tracking or tag-switching onto whoever cycles through.) Lively says the Mavs asked him to pick up that coverage in his first training camp, so he entered the league tasked with the responsibility of being, in his words, "a defender who could guard anybody and also cover for everybody."
"If I'm guarding someone who doesn't shoot, I've gotta control the paint and tell all my teammates where to go," Lively said. "If someone gets back-cut, I gotta be able to cover that. If someone gets blown by, I gotta be able to cover them. It takes a lot of trial and error and a lot of trust between you and your teammates.
"It's also knowing the player personnel, knowing who's comfortable enough and confident enough to shoot, knowing who you need to close out on. And then if they're putting it on the floor, making sure they're going to their nondominant hand and making them as uncomfortable as possible."
Lively's ability to excel in that role as a rookie was a big part of Dallas' playoff run, especially its second-round triumph over the top-seeded Oklahoma City Thunder. Throughout the series, the Mavs primarily guarded multitalented 7-footer Chet Holmgren with 6-foot-7 forward P.J. Washington while sticking their own centers on non-spacing guard Josh Giddey or Lu Dort.
That coverage helped short-circuit OKC's offense, even though it was nothing new for the Thunder; they've been cross-matched by virtually every NBA defense over the last two seasons. Coach Mark Daigneault chalks it up mostly to the challenge of guarding Holmgren.
"He's so versatile that he's basically a perimeter player, and when you start looking at how to match to him, that sometimes becomes the best solution," Daigneault said. "So I think it speaks to that trend offensively in the NBA, and the skill of some of the bigger players in the league."
It's true that centers with Holmgren's skill set make the guards and wings playing alongside them more likely to see cross-matches. Holiday's seeing them because he plays next to stretch-fives in Horford and Kristaps Porzingis. Hart is seeing them way more this season because Karl-Anthony Towns showed up to play the five in New York. Victor Wembanyama's San Antonio Spurs teammates will have to deal with them for most of his career, as rookie guard Stephon Castle has quickly discovered.
But in some ways, the coverage also bets against modern big men being able to punish height mismatches. Bigs like Holmgren and Wembanyama, talented as they are, don't typically enter the league with developed post games or body types conducive to backing down shorter defenders with lower centers of gravity. That gets especially dicey with help defenders prowling and swiping at bigs' high dribbles, not to mention the roving center lurking with back-side help.
"We can take the big out of the play if he goes to set a screen," Holiday explained, alluding to Boston's ability to take away lobs or pick-and-pop threes by switching. "Or, if he posts me up, I know that KP or somebody else is behind me if he ever gets too close to the rim."
Jokic is the rare big who has passing and shooting skill and post footwork and mismatch-mashing brutality in spades. For now, players like Holmgren and Wembanyama are more likely to attack a size mismatch by shooting over the top than by putting their defender in the basket, and the former is often a mid-range attempt that the defense is willing to live with.
Lively isn't a shooting big, but he came into the league as both a high-flying lob threat and a polished short-roll playmaker, which makes it dangerous to drop or blitz Dallas in the pick-and-roll when he's screening. He had a hard time accessing either of those skills in the Finals, though, when Boston put a smaller defender on him (usually Jayson Tatum, sometimes Holiday), put Porzingis on Derrick Jones Jr., and switched nearly every ball screen. Lively suggested the best way to beat that coverage is speed, not force.
"When they do that, we've just gotta be able to play the passing game," he said. "You know, drive, kick, swing, re-drive. And for me, it's just finding the open space, sealing, or getting to the other side. So whoever's guarding me has to make a decision whether to help and give up a laydown or stay with me and give up a layup."
Of course, while skilled bigs may be the biggest impetus for cross-matching, the coverage puts poor-shooting smalls under the most pressure. The stakes for them can become almost existential; they risk being marginalized or played off the floor if they can't make the defense pay, especially in the playoffs. A decade ago, Tony Allen became the first major casualty of that strategy. Giddey was the most recent, and he won't be the last.
Trading Giddey this past offseason didn't stop opponents from guarding the Thunder's centers with wings and their wings with centers, even with the non-shooting Isaiah Hartenstein playing in the injured Holmgren's place. Dort, Cason Wallace, Aaron Wiggins, and Alex Caruso have all gotten the cross-matching treatment from opposing bigs. Sometimes it's a defense's only hope of deterring OKC's army of drivers.
Caruso, who arrived in the trade that sent Giddey to the Chicago Bulls, knew to expect it coming into the season.
"I saw some of that in film that I was watching in preseason," Caruso said. "For me, I know they're gonna go help a lot at the rim, so it's just trying to be more aggressive. When our guards are getting downhill, the big's gonna stay there, so I know that I'm gonna get pop-back threes. Or the big's gonna be playing off me, so I know I'll have space to put it down and attack or get to the next action."
Caruso is having the worst 3-point shooting season of his career, hitting just 28.6% from deep, including 26.4% on wide-open threes. But he believes in his track record as a shooter - he's knocked down 37% of his long-range shots over his career, including 41% on nearly five attempts per game just last season. If he's concerned about what'll happen if playoff defenses treat him the same way they treated Giddey, he certainly won't cop to it.
"If they do that, I'm gonna shoot the shit out of the ball, and they're gonna have to find something else to do," Caruso insisted.
As for Giddey, he's still dealing with cross-matches in Chicago despite playing next to Nikola Vucevic, a more traditional center (albeit still one with some stretch to his game). Giddey is letting threes fly, attempting them at the highest rate of his career. But since he's hitting just 31.9% from deep this season and 31.2% for his career, that willingness alone won't impact the way teams guard him.
"I've had to learn how to play against it. Shooting threes is the easy answer, but there's a lot of things you can do to it," Giddey said. "Getting out and running is the first one. That makes them cross-match all over the floor, not just one position."
To wit: The Bulls, who ranked dead last in transition frequency last season, have jumped all the way up to second with Giddey aboard.
He and coach Billy Donovan also both spoke to the importance of Giddey becoming a screener, a sentiment that Donovan almost presented in the form of a challenge.
"He needs to get good at that," Donovan said. "He needs to be able to slip out and roll, try to create some confusion. Because when a center is on him, if he's coming up and screening for another guard, that's a little bit of a different switch for most big men. And because of his size and his passing, he's a bigger target (on the roll). It's not like they're putting a center on a guy that's 6-foot-2."
"It's taking time," Giddey said, "but I think I'm getting better at it. And I think screening has been the big one for me. Just learning how to do that, and working with the guards on that. Getting below the (on-ball defender) so I can get a low angle to get these guards downhill, and then get myself into the pocket to make plays out of there.
"But yeah, it's not all about sitting behind the 3-point line, just letting threes fly. That kind of plays into their hands. It's making yourself tough to guard by continuing to move, screen, be a threat all over the floor. Just keeping the big honest, so they can't stand in one place and kind of scour the court."
Giddey and Caruso also diverge in their approaches to spotting up away from the play when being guarded by a center. For Giddey, it's mostly about trying to get to the corner.
"That's the most efficient 3-point shot you can take, so if they want to give up corner threes, I'm happy to take them," he said.
Caruso has a different notion.
"The idea is to put the big on somebody that they think they can leave and then rotate to, but if I'm on the wing, the big has to guard me from the elbow or from the nail," he explained. "And that's something that they're not comfortable with, something they're not used to doing."
Caruso took an identical share of corner and non-corner 3-pointers two years ago, but he's now taking nearly three times as many of them from above the break. Giddey is correct about corner threes being more efficient (both guys are shooting 40% from the corners, but well below 30% from above the break), but Caruso is also right about how his positioning can mess with opponents' help points. It's why a lot of teams have started stationing their non-shooting centers in the weak-side slot.
One way or another, cross-matching will continue to affect the way certain players conceptualize their roles and the way certain teams game plan, particularly as we inch closer to springtime. Even the best teams in the league are susceptible to discombobulation if they aren't ultra-prepared.
"We weren't seeing as many (cross-matches) when we were winning 20-something games a season, but when you get better, teams honor that and start giving you all kinds of different pitches," Daigneault said. "Those are sometimes unconventional and uncomfortable, but we'd rather be working through them in December than get to a place where we're seeing them for the first time in high-stakes games."
Joe Wolfond covers the NBA for theScore.
