It’s the nature of the business to parcel out credit and blame: Who left Kawhi Leonard open for that corner 3? Whose fault is it that Tiago Splitter just lofted an easy layup over the front of the rim (because Splitter, even if he were 9 feet tall, would not dunk)?

But sometimes two great teams play against each other, and one team’s greatness forces the other into uncomfortable situations — tight places where even great teams make poor choices. The Heat were bad defensively for most of Game 3, especially in the first half, when San Antonio rained hellfire from everywhere, in a half-dozen languages.

But credit the Spurs for putting Miami under pressure — for creating a scientific state in which glitches happen.

Take this Tony Parker–Tim Duncan pick-and-roll that starts with Parker zooming off a pick at the left elbow as Leonard, in a canny bit of cutting, circles behind him along the baseline toward the left corner:

Duncan’s man, Chris Andersen, slides off the big fella to help Dwyane Wade corral Parker. Wade was guarding Parker here because Miami was playing without either of its point guards, a distressed step it is taking more in this series that at any point this season, mostly because Mario Chalmers has forgotten how to play basketball at the worst possible time.

With Parker going right, toward the middle, LeBron has the job of rotating off Leonard to body-check Duncan in the paint. All appears well.

But Andersen has given Parker enough space to see the floor, and as he pulls up to pass the ball, he puts LeBron in a difficult position: Is he going to pass to Leonard or Duncan? LeBron takes the bait and bolts at Leonard, something he can do with a bit of confidence, since he knows Andersen should be bolting back toward Duncan:

It’s too late: Parker has cracked open a window just big enough to slide a pass to Duncan — a pass that threads between James and Andersen, and finds Duncan before Ray Allen can make the next emergency rotation from the right corner. Does LeBron abandon Duncan too early, misread Parker, or get a little greedy hoping to swipe a pass to Leonard that never comes? Maybe. But the Spurs force those kinds of choices upon opposing defenses, and they are smart and talented enough to make sure a lot of those choices turn out wrong. San Antonio is constantly finding those little in-between windows and smashing through them with the kind of decisiveness required against an athletic beast of a team like Miami.

And when enough shots start to fall, even champions can panic. Parker found Boris Diaw for a corner 3 near the end of the first half on a play that starts with Duncan setting a pick just to Parker’s right — a pick that gets Andersen to jump out in that direction:

But Parker doesn’t go right. He reverses course, and Duncan does an artful little thing: He flips the direction of the pick, so that he’s now standing to Parker’s left, and Andersen is out to dry on the right side:

All of San Antonio’s bigs are great at this little screen-flipping trick. It is a mandatory skill for them. Parker gets a head of steam going left into the paint, but Andersen does a nice job of sliding down with him. Problem: Chris Bosh, guarding Diaw, reacts as if a crisis is afoot and bolts far into the paint to deter a Parker drive:

Is it a bad choice? Maybe. It certainly opened up the Parker-to-Diaw pass. But it’s the kind of choice an uncertain team makes after the league’s prettiest offense has sliced it up for 23 minutes.

You can’t really stop San Antonio over 48 minutes. It will create a certain number of open looks every game, and some nights it will make more of them than you’d expect. Your defense will slip up now and then under duress. No team is immune. But to beat the Spurs, you have to bring your A-game the rest of the time. You can’t help them by playing subpar defense and coughing up the ball.

Miami gave the Spurs that kind of help in the first half, and now it is staring at a must-win on Thursday. Wade and Chalmers botched two handoffs within the first five minutes of the game, leading to two San Antonio fast-break buckets. Splitter scored an easy layup over Allen after the Heat switched a high pick-and-roll, only Allen did so too late to stay in front of Splitter:

Danny Green beat Bosh for a driving floater early in the second quarter after Wade moped in the backcourt, failed to get on defense, and left Bosh holding the bag. Patty Mills nailed a pull-up 3 to put the Spurs up 20 by rocketing past an uninterested Wade after the Spurs swiped the ball from Allen under the rim, with Wade just standing there, doing nothing.

Green hit an open 3 after switching places with Diaw along the perimeter, a simple action that confused Miami; two defenders tracked Diaw, and LeBron was too late in realizing Green had sprung open. Chalmers absolutely died on this Splitter pick for Parker, who then raced in for an uncontested layup, all the potential help defenders basically shrugging:

There were more. It was ugly, at least until the third quarter, when Miami turned up the urgency, including during the team’s first strong stretch of the series with LeBron on the bench — a stretch in which Wade was phenomenal on both ends. But you can’t spot a team as good as San Antonio such a huge lead, not even at home.

Just make sure to credit the Spurs for sensing weakness, taking advantage of it, and even creating some of Miami’s defensive fragility. Every Spur was decisive with the ball. Here’s Diaw about to catch a pass after screening for Manu Ginobili:

Diaw’s guy, Bosh, has trapped Ginobili hard, and Andersen is rotating off Splitter to contain Diaw. The large bearded man with the crazy tattoos did not flummox Diaw at all. Diaw did not pause for a millisecond. He dribbled the ball hard right at Andersen, getting to the basket, drawing defenders, and forcing rotations that left Mills open on the outside:

The easier pass here would be to find Marco Belinelli in the left corner. But would you look at the freaking insane blind pass Diaw somehow wrapped around to Mills:

I mean … take a bow, Boris. Mills swung it to Ginobili, who missed a wide-open 3. The process was brilliant. The execution before the shot was even better. The Spurs put on a masterpiece, and the Heat nudged them along.

Some Other Thoughts From Miami:

• We didn’t see Diaw start any meaningful possession guarding LeBron. James has figured that matchup out, and, really, he did it by Game 6 of last year’s Finals. Diaw’s mastery of James has been overstated. That said, it can work as a change-of-pace tactic, and Pop abandoning it Tuesday doesn’t mean we won’t see it again.

• The Spurs switched a lot more in this game than they had in Games 1 and 2, and it seemed to unnerve Miami a bit. A few of the Heat’s 20 turnovers came when they tried to attack the mismatches those switches produced, only to drive into a swarm of reaching arms.

• Fun halftime bathroom scene: Two San Antonio fans, wearing Spurs T-shirts, were waiting in line when a Heat arena custodian noticed them. He taunted, “This bathroom is for champions.” They fired right back: “Oh, we’re in San Antonio?”

• Negative points to the woman wearing the pink Tony Parker jersey.

• Positive points to the guy wearing a Ginobili Argentina national team jersey.

• That was probably Leonard’s finest two-way game, considering the stakes. He was ridiculous. He lost his mind. He defended LeBron below the 3-point arc about as well as possible, staying in front of him, bodying him up in the post, and staying down on pump fakes. On one early fourth-quarter play, LeBron drove on Leonard from the middle of the foul line, and Leonard just stuck right in his jersey. LeBron got near the baseline, pump-faked a couple of times, and found himself trapped by Leonard’s mega-arms.

He meekly kicked the ball to Norris Cole in the corner, and Green promptly slapped the thing out of Cole’s hands for a steal. It would be literally impossible for two wing defenders to play better defense on one play, short of Leonard acquiring a ray gun and vaporizing LeBron on the spot. But Green told me after the game that he didn’t take a moment, even in the locker room, to really appreciate it. “No,” he said, laughing a bit. “We know what we’re capable of, and we know how good that team is. They’re going to be good. We just have to be better.”

• Some of Leonard’s jumpers were well-contested shots that just went in.

• We have seen very little of the battle a lot of us expected to headline this series, or at least large portions of crunch time: a big San Antonio lineup, likely the Diaw-Duncan combo, going up against the super-small Heat lineups featuring Wade, Allen, James, Bosh, and one point guard.

Erik Spoelstra went with one of those groups (the Cole version) early in the fourth quarter with the Heat down 11, and the Spurs responded by having Diaw guard Wade — as they had briefly in Game 2.

Gregg Popovich countered about two minutes later by swapping Mills for Diaw, going small, with Leonard at power forward. Leonard got a dunk and a steal right away, the latter via more sensational one-on-one defense against James, and Spoelstra quickly went back to the Rashard Lewis–Bosh combination.

The Miami super-small lineups have logged less than 10 minutes combined over three games, per NBA.com. Lewis has played well, but he’s not dangerous enough to get the Spurs out of their comfort zone. They’ve played two bigs for the huge majority of the series, and they much prefer that to going smaller. The Heat have not yet been able to force Popovich’s hand as they did last season.

• That small-versus-big action gets doubly interesting when LeBron sticks on Parker, since it means one of Miami’s “bigs” in this alignment is guarding the smallest Spur. That has ripple effects across all other matchups, and the Spurs should be able to find a favorable post-up out of it.

We didn’t see LeBron on Parker quite as much this game, and when it began to work, Pop cannily pulled Parker for Mills. The Heat normalized their matchups, with LeBron going back onto Leonard, and the Spurs settled down.

• “Everybody should have their glow sticks ready.” —A thing the Heat’s PA announcer actually said to the crowd before the introduction of the starting lineups.

• I love LeBron’s national anthem theatricality. As Julia Dale, the girl who sings the anthem here for every playoff game, reaches “home of the brave,” James begins pounding his chest and pointing to the sky. Right as Dale concludes “brave,” he rips open his warmup jacket. He knows the cameras are showing him on the JumboTron. It’s a cool moment.

• Two Miami fans behind me, with about 3:00 left and the crowd streaming out: “Don’t leave! Remember Game 6!???!” They were joking to get attention, but don’t accuse the media of prolonging the Game 6 early-exit humiliation for Heat fans. They are doing it themselves.

• Burnie, the Heat’s mascot, is some sort of anthropomorphic flame. He has a basketball for a nose. Basketballs are orange, and so Burnie’s nose is normally orange. But with the Heat in whiteout mode for the playoffs, he’s using a special white basketball for his nose. I disapprove.

• Miami has turned the ball over on 19.9 percent of its possessions in this series, a number that would have been the worst in the league for the season by a mile. They are usually the team causing turnover issues; ask Ginobili about last year’s Finals. It is hard to win while losing the turnover battle to the league’s most polished offensive team.

• One bonus of starting Diaw: He provides a one-on-one option to bail the Spurs out of possessions that aren’t going anywhere. In the last two games, he has had multiple drives against Lewis that start beyond the arc and somehow end in post-ups near the rim. Diaw is a nifty player.

• The Spurs also know they can throw the ball to Duncan in the post against Bosh and (especially) Andersen, and at least get some traction — a good look for Duncan, a foul, some bending help defense from Miami.

• I like Popovich at least trying Matt Bonner during some of Lewis’s minutes. He helps with spacing, and Lewis can’t really punish him on the other end. It’s worth a shot, and Pop is yanking Bonner the minute Lewis comes off the floor.

• One thing that Miami small-ball lineup enables: some old-school pick-and-roll ball from LeBron up top. That’s normally too stagnant to work well against good defenses; the Heat, like any good offense today, preface their pick-and-rolls with some cutting and misdirection to get the defense off-balance. Coaches call it “fluff.”

But with so much space on the floor, a simple LeBron/Bosh pick-and-roll is damn hard to guard, and the Heat got Allen a corner 3 in the fourth quarter around that basic action. Bosh was also slipping picks in this game, hoops lingo for cutting hard to the rim before really setting the pick. Watch for that in Game 4.

• Spurs officials said Leonard asked out of the podium treatment. He has had one podium game this playoffs, so it’s not as if he’s unfamiliar with it. If he plays this well again, I’m not sure he’ll have a choice.