Sam Presti, the Thunder's general manager, does nothing by accident, and so ears perked up during preseason media sessions when he added Steven Adams name to the list of Thunder core players alongside Kevin Durant, Russell Westbrook and Serge Ibaka.

It was Presti code that after just two seasons, the Thunder were comfortable that Adams fit their basketball identity -- both as a person and as a player with a very specific skill set the team covets. He's team-first, willing to do the physical grunt work that frees Durant and Westbrook to fly. He's massive and immovable, symbolic of the Thunder's belief that even as the NBA gets smaller and faster, the right sort of size at every position can trump everything.

And for the third straight playoff series, Oklahoma City's collective size and speed are unnerving the Spurs' beautiful game. Zoom way out, and it appears nothing much has changed about the Spurs' offense over the past three games in which the Thunder decided to actually try. San Antonio is shooting the same number of midrange shots, 3s and free throws as it did in the regular season. Although it feels like the Spurs are rubbing up against the shot clock on almost every trip, the percentage of their shots heaved in the final six seconds of possessions has barely budged from their season-long average, per SportVU data from Stats LLC.

Their quantified shot quality, a SportVU-derived stat of the field goal percentage we'd expect a team to hit given the Spurs' shot profile, sits at 49.5 percent over those past three games. That number looks bad. It is also exactly what San Antonio averaged for the season.

But there have been changes on the fringes. The Spurs are getting fewer spot-up shots, the best looks in the game, indicating the Thunder are running them off the arc -- and forcing the Spurs to cycle through second, third and fourth options. They have become more dependent on LaMarcus Aldridge in the post and Tony Parker on the pick-and-roll. They have scored just 99 points per 100 possessions over those past three games, about 10 points below their season average, and hit a miserable 48 percent on shots in the restricted area -- a mark that would have ranked last by a mile for the season, per NBA.com.

That's where Adams has been living for an astonishing 38 minutes per game over the past three battles, a full 13 minutes more than he logged on average during the season. Adams wouldn't be able to play that much had he not found ways to make himself an offensive threat -- methods that would translate into any team context, and little skills-within-skills that mesh snugly on a team with two uber stars who are going to have the ball almost all the time.

One little Adams trick flipped Game 4 on its head:

That play from the second quarter started as a typical Thunder set: Adams setting a pin-down screen for Durant. As he barreled down, Adams noticed his man, David West, cheating away from him to at least flash in Durant's line of vision as Durant rocketed off that Adams pick.

In that moment, Adams saw an opportunity to make himself dangerous. He aborted the screen, took a left turn and rose for an uncontested alley-oop. This little read caught the Spurs by surprise. Billy Donovan and his staff deserve a lot of credit for sniffing this fissure out on film and exploiting it over and over.

San Antonio's potential help defenders on the left side of the floor aren't even looking at the Adams/Durant action, fixated on Ibaka setting his own pin-down screen for The Once and Future King of Waiters Island. That decoy keeps the Spurs' defenders busy because Dion Waiters is actually a threat to do something with the ball if he gets it.

Andre Roberson is not, which is why Parker zoomed in early to barely break up another slippery Adams cut in the third quarter:

The Thunder don't need to remove Roberson from the starting lineup. They've won two of the past three games, and their starters have outscored San Antonio by 11 points in 50 minutes over that stretch. But they are always threading a tiny needle with Roberson. Their defense has to be incredible to survive all the damage Roberson inflicts on their offense. They've done that over the past three games, in part because Tim Duncan has been awful, but Donovan has to be ready to cut bait fast if things turn.

Regardless: Adams' discovery of a reliable path to points via one simple-looking cut changed the game, and maybe the series. The Thunder over the first three games had often used Roberson to set that same screen for Durant, and it didn't work; the Spurs just abandoned Roberson and doubled Durant. Adams short-circuited that idea, and the Spurs responded by switching that Adams/Durant pin-down for much of the second half.

Sometimes it worked; Leonard drew a charge here on one of about 10 incredible defensive plays he made on Sunday:

Seriously: That one steal he had along the right sideline, where he extended his arm as far as he could to deflect a pass before deciding, "Oh, hey, I'm Kawhi Leonard, and I can just catch this ball" -- that was insane. Maybe every other player in the league waps that ball out of bounds. Leonard swallowed it with one hand. Between that play, some vintage Danny Green transition defense, and two gamblin' steals from Manu Ginobili where he almost looked like a lunging fencer, the Spurs generated at least a dozen highlights on defense -- and still lost. My god, the Thunder can be special.

Back to Adams: That switch left a big man on Durant, and Durant can roast any one of the Spurs' bigs. The Spurs crowded the lane, forcing Durant to pass, and sometimes that was enough to win a possession:

But this same drive-and-kick action got Waiters a monster triple in the fourth quarter, and even when the Spurs re-switched to put a smaller player on Durant -- Patty Mills in the clip below -- the mismatch drew so much attention that Thunder role players could thrive in the void:

As I wrote in February, the Thunder offense now mostly belongs to Westbrook. The pick-and-roll division of labor has skewed dramatically in his direction, away from Durant, and the Westbrook-Adams spread pick-and-roll has been unstoppable in this series. It is probably the Thunder's best play, even if it turns Durant into a spot-up shooter whose main job is to suck a defender out of the lane.

Durant's pick-and-rolls are harder work. He's a gangly dribbler, and he doesn't have the same north-south explosiveness as Westbrook. No one does. Defenders sag way off Westbrook, so that Durant navigates tighter spaces with his high dribble. He can do it, because he's Kevin freaking Durant, but it's not as easy.

That has left Durant to take a ton of hard shots -- Dirk fadeaways in the post, one-on-one runners, off-the-dribble 3s on the pick-and-roll. That Adams cut opened up a cleaner path for Durant to attack with the ball, and he eviscerated the Spurs. We all would like the Thunder to share the ball more and imitate the Warriors and Spurs. That isn't in their DNA, and sometimes it doesn't really matter. When you can manipulate the chess pieces in ways that get two of the best half-dozen players alive favorable matchups, the path there doesn't have to look nice.

(As an aside, the Spurs even switched Enes Kanter pin-downs for Durant, leaving Leonard or Green on Kanter. The Thunder didn't look to post Kanter against those smaller guys, and that may be another path to explore in Game 5.)

That little read by Adams looks simple. So do all the lob dunks he gets now on the pick-and-roll with Westbrook.

They're not. They require the kind of feel and chemistry that only comes from repetition. "There's a subtle timing aspect that goes into rolling like that," Nick Collison told me in February during a chat on Adams' progress. "He has a much better feel for it, and Russ is finding him. You have to learn to time your momentum going into the catch, as opposed to just rolling in and randomly thinking, 'Oh, the lob is there.'"

If that exact cut looks familiar, it might be because another brainy center from the opposite end of the globe has mastered it in Golden State while fake-screening for another elite shooter:

"He's become a big-time roller," Westbrook said of Adams in February. During a chat with Adams, I mentioned that at times, he almost looked like Tyson Chandler rising for lob dunk after lob dunk during his heyday with Dallas.

"Tyson Chandler, huh?" Adams said with a laugh. "I guess I'm just making better reads, and Russ and I are getting more comfortable with it. That's pretty much it, isn't it?"

Adams has been the Thunder's third-best player in this series, and he's been so good, Donovan feels emboldened to stretch the gigantic Kanter-Adams double-mustache look over extended minutes. The two behemoths have shared the floor for 36 minutes total over the past three games, and the Thunder have blitzed San Antonio by 12 points over that span, per NBA.com.

The Thunder didn't start experimenting with that look until February, and the two centers played only 127 minutes total over 27 games during the regular season. They have Voltron-ed into a weapon against the Spurs. Oklahoma City has rebounded a preposterous 48 percent of its own misses with those two on the floor over the past three games, per NBA.com.

They are just too big and strong for the West-Boris Diaw combination. Those fogies can't compete with Adams-Kanter on the glass, or finish over them on offense. The Spurs suddenly look one big man short. It has never felt more like we are witnessing the final days of Timothy Theodore Duncan. Somewhere over the past few months -- maybe due to a groin injury that sapped some of his conditioning -- Diaw lost a quarter-step or so. And that can mean everything when you can barely jump, and rely on guile to meander your way into flippy shots and silky bankers.

It's tempting to suggest that Gregg Popovich experiment again with going smaller, using Leonard at power forward and Aldridge at center. They could switch that Adams/Durant pin-down, and lots of other actions, without locking themselves into fatal mismatches. Kyle Anderson gave the Spurs six good minutes in which he didn't look out of his depth guarding Durant.

But over time, you wonder if Anderson could really hold up. Jonathon Simmons showed hoppy promise during the season, but the coaching staff clearly doesn't trust him now. Even mainstays Ginobili and Green have been hit-or-miss on offense. The Spurs feel a wing short of going small and a big short of playing the way they really want to play. And if they ever did dare go small against Adams-Kanter, they would risk a bludgeoning on the boards so bad as to negate any speed and shooting advantage.

The Spurs stole home-court advantage back by winning Game 3. They're going home now for a pivotal Game 5, and they are endlessly confident in their ability to execute under pressure -- and in Oklahoma City's making just enough mistakes to lose a game. They might poke at Kanter more if Donovan dares put him on Aldridge again in crunch time, but a rewatch of Game 4 shows they tossed Kanter into a bunch of Parker-Aldridge pick-and-rolls over the last five minutes.

Popovich will have new wrinkles. Leonard might do better against Roberson and Waiters until Durant decides to take the challenge of guarding him the entire game. The Spurs might just have their bigs stay home on Adams, and dare Durant to beat Leonard by turning the corner -- a strategy that is cleaner with Roberson on the weak side.

But the Thunder have showed, again, that they can compete with a Spurs team that looks better -- and is better -- over the long haul, against the entire league. That is what makes Oklahoma City's Game 1 no-show so infuriating.

Nothing to do about that now. Game 5 is a massive moment for both franchises -- a moment we need as the Cavs vacation, Stephen Curry rests and the Raptors and Heat play 1990s Eastern Conference basketball without the headlining centers. Adams changed this delightful, tense series in Game 4. Let's see who steps up on Tuesday.