Thunder-Mavs has become a defensive slugfest

When Shai Gilgeous-Alexander shook loose for 22 second-half points to help Oklahoma City claw out a momentous come-from-behind Game 4 win in Dallas - a game the Thunder trailed for over 41 minutes - it felt all the more impressive because of how hellish the Mavericks were making life for OKC's offense.

Bodies were swarming everywhere, rotations were made in perfect synchronicity, only shaky shooters were left open on the perimeter, and the paint was a no-fly zone. The Thunder were hesitant to shoot and were skittish around the rim. Dereck Lively and Daniel Gafford were in their heads, and finding any sliver of space felt like a win.

Gilgeous-Alexander finished with 34 points, and not a single one of them came from beyond the arc or inside the restricted area. Only six came at the free-throw line. It took all he had just to wriggle free of Derrick Jones Jr. and P.J. Washington and a bramble of surrounding arms to let fly a flurry of contested 16-footers. All told, the Thunder compiled 28% of their points on mid-range jumpers, the highest proportion for any team in a game this postseason. (Only one other game even saw a team clear 20%.) They somehow managed to win a contest in which they shot 26% from deep, 35% at the rim, and 33% from floater range.

They were able to do that because of Shai's heroics - both the contorting pull-up middies and the relentless drives that eventually produced some timely threes from his teammates. But more than that, they were able to do so because the Mavs struggled just as badly at the other end, with 11 clanked free throws nailing their coffin shut.

Dallas had scantly more success finishing around Chet Holmgren than OKC did going at Lively or Gafford. A hobbled Luka Doncic managed just 18 points on 30 used possessions, with more turnovers than made field goals. Kyrie Irving registered just 12 true shot attempts while being shadowed by the Thunder's army of point-of-attack defenders, including rookie Cason Wallace for the whole fourth quarter.

The series, which now returns to Oklahoma City knotted at two games apiece, has become a defensive slugfest, which isn't necessarily what you would've expected out of a clash between the NBA's third- and eighth-ranked regular-season offenses. To be fair, the Thunder also ranked fourth in defensive efficiency, while the Mavs ranked sixth after adding Gafford and Washington at the trade deadline. But it's still been surprising to see a matchup featuring two top-three MVP finishers (Doncic and Gilgeous-Alexander) and two of the most dynamic complementary creators in the sport (Irving and Jalen Williams) get dragged into knee-deep sludge.

The Thunder and Mavs own offensive ratings of 111.2 and 108.1 in this series, respectively, which is down from 118.3 and 117 during the regular season. The biggest factor in that scoring suppression is the work both defenses have done on the interior, which the officiating has aided. OKC is shooting just 57.3% inside of 4 feet, while Dallas is at 51%, ranking them seventh and eighth among the eight second-round teams, per Cleaning the Glass. (For context, Portland was the league's worst rim-finishing team this season at 60.3%.)

That's primarily attributable to the three central big men, who have all showcased their incredible short-area agility and vertical athleticism while functionally playing goalie:

Not for nothing, these teams have also attempted rim shots at the two lowest rates in the conference semis, so deterrence has been a big factor here as well.

That's a particularly impressive feat for Dallas, considering the Thunder are built to drive the ball and drive it again and then drive it some more. (Their 66 drives per game are 14 more than any other team this round.) The Mavs' offense, by contrast, mainly applies rim pressure via the team's hard-rolling bigs. Each defensive scheme has been tailored to limit the opposing offense's preferred avenues to close-range buckets.

In Dallas' case, that means refusing to play ball with OKC's purported five-out spacing. The Mavs' centers simply aren't matching up against Holmgren, whether Josh Giddey's on the court or not. (Mostly not; Giddey's played just 53 minutes across these first four games, which has arguably still been 53 too many.) When Giddey hits the pine, Gafford or Lively shifts to nominally guarding whichever other Thunder player is deemed to be least threatening on the perimeter. That might be backup center Jaylin Williams or a low-usage wing like Lu Dort, Aaron Wiggins, or Gordon Hayward. (Hayward is more like a no-usage wing at this point and probably needs to be shelved too.)

Most of the time Dallas doesn't even have its center guarding anyone in particular but rather playing a one-man zone in which he can stay anchored on the lower half of the defense. In that scheme, Gafford or Lively will 2.9 in and out of the paint while being tangentially responsible for the weak-side corner shooter and/or whoever flashes into the dunker spot. (OKC likes to invert its spacing by putting a guard or wing there.)

That back-line safety net, coupled with the fact that Irving and Doncic are playing the best defense of their careers, has emboldened Dallas to switch a lot of the Thunder's screening actions, even when it means conceding a favorable individual matchup to Gilgeous-Alexander or Williams. In doing so, the Mavs have flattened out OKC's quick-hitting screen-and-slip attack without getting burned too badly on the front end of those switches, at least not by Williams. It certainly helps that they can survive having a wing on Holmgren at all times, which is kind of a Holmgren problem right now.

There are certainly things the Thunder can do better - i.e. increase their weak-side activity, get their non-shooters involved in more ball screens and dribble-handoffs, utilize the skip pass more, be less rigid in their dunker-spot usage - to make those Dallas bigs account for more space. But you have to credit the Mavs for constantly working to take that space away. Jones Jr. and Washington have been tremendous on the ball and in the gaps. Irving is flying around off-ball and seemingly deflecting everything in his vicinity. Even Doncic is taking breaks from working the refs for long enough to help and recover with zeal, balky knee and all.

The Thunder, meanwhile, continue to gear their defensive game plan toward stymieing Doncic's progress in the middle of the floor, getting the ball out of Irving's hands, and tagging aggressively to deter Gafford and Lively on the roll. Doncic is obviously operating well south of 100%, but holding him to 49% true shooting is still a laudable achievement for Dort and Co. So is holding Lively and Gafford to a combined 44% shooting after the two combined to shoot 76% during the regular season. And while Irving has solved the aggressive coverages he's seen with some dazzling passing, it's hard to fault OKC's process when he ranks sixth on his team in usage rate (17.6%) for the series.

The Thunder's paint-packing scheme continued to get burned by Washington's scalding-hot shooting in Game 4, as he hit a game-high five triples and is now 19-for-37 from deep in the second round. (No one else in the series has hit more than nine threes.) But the Thunder have clearly decided they're willing to live with the results of conceding open looks to a 35% career 3-point shooter who hit just 33% of his wide-open threes as a Maverick during the regular season.

And while everyone is rightly lauding the Mavs' star duo for elevating itself to a new level at the defensive end, that level is still a few notches below the stratum Gilgeous-Alexander and Williams occupy all the time. Both have been exceptional within OKC's pressure-and-rotate scheme this series, especially Gilgeous-Alexander, who's averaging 1.3 steals, 4.3 deflections (second only to Nikola Jokic), and 2.8 blocks - more than anyone besides Holmgren among second-round players.

Last but not least, let's give a tip of the cap to Holmgren for hauling in eight huge rebounds in the second half of Game 4 and limiting the Mavs to just five second-shot possessions. Defensive rebounding is the Thunder's Achilles' heel, and it sunk them in Game 3. But take the series as a whole, and they're holding up just fine. They've lost the offensive rebounding battle by a mere eight boards, leaving them on the winning end of the overall possession battle since they're plus-12 in turnover differential. Tradeoffs, tradeoffs, tradeoffs.

It feels like the Thunder are perpetually playing with fire, but maybe that fire has helped forge them into the steely playoff combatants we saw emerge from the smoking wreckage of Monday night's virtual must-win. They're a long way from being out of the woods, but in a series that's become a mud fight, they've proved they can sling dirt with the best of them.