Brad Stevens was supposed to be the next Mike Krzyzewski, and his school, Butler, had a chance to one day rise to the level of a Duke. Stevens had led the Bulldogs to upset after upset on their way to two straight national championship appearances. But then the Celtics sent shock waves through the basketball world by hiring the then-36-year-old away from college in July 2013. Krzyzewski called Stevens “outstanding” and a “terrific hire” for the Celtics. Syracuse coach Jim Boeheim said Stevens is the best young coach he had seen in his lifetime. Then–Bucknell coach Dave Paulsen called Stevens’s system at Butler “the best coaching clinic you can have.” Then–Marquette coach Buzz Williams said, “Coach Stevens is a Hall of Fame coach. He’s just not old enough for you to call him that yet.”

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Great college coaches like Rick Pitino and John Calipari made the leap to the NBA and failed, but Stevens was different. Expectations have been high, but both he and his Celtics have continually exceeded them. A 2014-15 Celtics team that was supposed to tank ended up winning 40 games. They won 48 the following season. And in 2016-17, they had an above-average defense despite an undersized backcourt featuring Isaiah Thomas and made a run to the Eastern Conference finals. Then, after Celtics president of basketball operations Danny Ainge blew up the roster last summer and left only four returning players, Stevens basically had to start from scratch.

Integrating new players didn’t end at training camp. The Celtics lost Gordon Hayward, their star free-agent signing, five minutes into the season, only to reel off 16 straight wins. They lost Kyrie Irving in March, and Stevens revised the team again by inserting Terry Rozier into the starting lineup and funneling more of the offense to Jayson Tatum and Al Horford. Two months later, a depleted Celtics roster is on the cusp of beating the favored Sixers on its way to a second consecutive East finals.

Led by Joel Embiid, 24, and Ben Simmons, 21, the Sixers have one of the brightest futures in the league. And after rattling off 16 straight wins themselves to finish the regular season 52-30 overall, then handling the Heat in the first round, they looked to be far ahead of schedule. I picked them to beat the Celtics, as did most others. But Stevens has taken a roster full of players with the versatility to defend multiple positions and maximized their talents, much like he did at Butler, to put Boston up 3-0 heading into Monday’s Game 4 in Philadelphia.

Stevens has simultaneously shown just how talented a coach he is and how far the Sixers are from taking the big step to becoming true contenders. Here’s how he’s done it:

Pulling Embiid Away From the Rim

Stevens works his magic in many ways, but in Game 3 on Saturday it was his play-calling that stole the show. Knowing that the Sixers would switch all screens, Stevens called a play near the end of regulation that pulled Embiid out of the paint to open it up for a pass to Jaylen Brown, who hit the game-tying layup.

Then, with a chance to win in overtime, Stevens structured a play that looked like it was designed to get the ball to Tatum off a Horford screen. But the Sixers were denying the perimeter, so the inbounder, Marcus Morris, would’ve been forced into a tough pass. Stevens called a timeout and redesigned the play to take advantage of Philadelphia’s willingness to switch Robert Covington onto Horford.

Stevens painted his Mona Lisa in the huddle, and the players executed to perfection. Rozier sprinted into the backcourt, and T.J. McConnell followed. As the Celtics set screens on the baseline, Brown ran to the perimeter, and Embiid trailed him. Simmons aggressively denied Tatum. Covington was alone on an island against Horford, and a perfect entry pass put Horford in position for the bucket. “Brad is a genius, man,” Horford said in the postgame interview with ESPN. “Sometimes he draws stuff up and I look at him like, ‘I didn’t think [that’d work].’”

Both of those after-timeout plays worked because Embiid wasn’t inside to protect the rim, and drawing him away has been the key to the series. The Sixers are allowing a dismal 110.1 points per 100 possessions against the Celtics, a far cry from the 102.0 (third best in the NBA) their defense allowed during the regular season. Boston is taking Philly’s All-Defense–caliber center out of the paint by using Horford to space the floor.

This is too easy. Horford shot 42.9 percent from 3 this season; there’s no reason for him to be wide open. In Game 2, Embiid began closing out more aggressively on Horford, but that enabled him to attack.

Horford’s layup here clinched Game 2 for the Celtics. Embiid was tired and on his last legs, which was another bonus for Boston in making him defend the perimeter. (Embiid’s conditioning needs to improve over the offseason, which should be the first healthy one of his career. If Embiid can build on his already remarkable second season, the Sixers could be even better.)

Philly adjusted in Game 3 by putting Ersan Ilyasova on Horford and Embiid on Morris. The Celtics didn’t run as many screens with Horford; Stevens adjusted by having Horford post up on Ilyasova or running screen actions with Morris.

But it doesn’t help matters for Philadelphia that when Embiid is out of the paint, the Sixers haven’t been able to stop the ball. The Celtics play seek-and-destroy with Marco Belinelli when he’s in the game. Dario Saric looks physically outmatched by Morris. And Simmons is playing defense like he’s at LSU.

Simmons has allowed Rozier to blow by him or failed to hustle in transition on a number of occasions in this series. It’s tough to tell whether he’s fatigued after the longest season of his life. Nonetheless, the Sixers aren’t getting what they need from one of their most versatile players.

The irony is that when Embiid is out, Horford posts up. It’s simple, and it speaks more to Horford’s versatility than Stevens’s basketball intellect. But a coach’s role is to maximize his players, and Stevens is doing that. Forcing Embiid out of the paint has revealed Philly’s defensive flaws.

Slowing Down Simmons

All season, Simmons looked like a cyborg trained to execute basketball plays at the highest level. But he has been exposed against the Celtics. Here’s how Boston defends Simmons when the rookie brings the ball up the floor:

Aron Baynes stands at the free throw line with arms wide open, which clogs the lane and deters Simmons from attacking, thus hurting the rest of the Sixers’ half-court offense. As Ben Falk outlined on Cleaning the Glass, the Heat tried a similar strategy with Hassan Whiteside. But Whiteside was often out of position. Baynes has been better this season since he plays smart, hard, and consistently.

Stevens uses this technique on Simmons for three reasons:

1. The inbounder usually jogs slowly up the floor, so his defender—Baynes or someone else—can sit back and contain Simmons.

2. Simmons shoots with the wrong hand and is deathly afraid to launch from outside 18 feet. Until he proves he can hit a jumper, there’s no reason to defend him from outside.

3. The inbounder is often Embiid, who isn’t a real threat from 3-point range. The Celtics aren’t worried about him from behind the arc.

The Sixers can fix the first point by having Saric inbound or having the big man hustle up the floor. But the second two won’t change overnight. They are open-wound weaknesses for the Sixers, and Stevens has pressed his thumb harder on them than any team has before by sagging off of Simmons and helping off of Embiid.

Simmons’s devastating transition drives would often result in loud dunks or kick-out passes for 3. That usually has a carryover effect to his and the other Sixers’ games. Philly needs him to steamroll to have success against elite defenses. It’s stunning that the Sixers haven’t run more pick-and-roll with Embiid or a shooter like J.J. Redick screening for Simmons, which should be a wrinkle reinstalled over the offseason. But for their already-good offense to be as lethal as it can be, it’s critical that Embiid, a career 32.5 percent 3-point shooter including these playoffs, improves his shot because of the team’s makeup.

Simmons can’t shoot at all, and who knows what’s going on with Markelle Fultz, who has been relegated to the bench since Game 3 of the Heat series. So it’s on Embiid to develop into a player who can make defenses anxious when he’s standing at the arc. As of now, he’s doing opponents a favor when he’s out there.

Simmons is a supreme offensive talent, and he’s not going to face the league’s best defense all 82 games or in every playoff series. The Sixers should get better, too, which should alleviate the load on his shoulders. But he still needs to turn himself into a player who can excel without the ball in his hands so that the stars around him can flourish. If the Sixers were to trade for Kawhi Leonard, for instance, there’d be little reason to defend Simmons off the ball, since he basically stands around, rarely cuts, and can’t shoot.

Giannis Antetokounmpo’s experience and more advanced scoring skill set pushed the Celtics to seven games before the Bucks bowed out. Simmons, meanwhile, is getting his first taste of what it takes to execute against an elite defense in a playoff series.

Using Single Coverage on Embiid

Simmons can still get the Sixers into their offense, but it’s frequently felt like their best options are players not named Simmons and Embiid. When Sixers fans are yelling on Twitter for T.J. McConnell to be in the game over the past two no. 1 picks, it’s a problem. When you think maybe a flare screen set for Belinelli is a better option than an Embiid post-up, it’s a problem.

Embiid has logged 42 post-ups against the Celtics and the Sixers have scored only 23 points on those plays, or a poor 0.55 points per possession, per Synergy.

The single coverage has baited Embiid into low-percentage hook shots 8 feet from the rim and contested pull-ups, and it’s taken away passing lanes for cuts. Stevens made a smart call deciding to double Embiid only when it was late in the clock:

Embiid has improved significantly in the post since he was a raw freshman at Kansas. But he has been challenged against two stellar defenders in Horford and Baynes. To make the leap from good to great as a post scorer, Embiid must become a player who demands a double-team by expanding his moves and mastering his existing ones.

Advantage: Stevens

The playoffs reveal players and teams for what they really are, and Stevens pulled back the curtain on the Sixers by thoroughly outcoaching Brett Brown and by exploiting Embiid and Simmons. Depending on whom you ask, Stevens is considered the best or second-best coach in the NBA. But at age 41, he certainly has more future value than 69-year-old Gregg Popovich, who is the best coach of this century.

We’re at the point when questions like this are being posed:

There’s not a single general manager who would take Stevens over Giannis in a draft that includes both players and coaches. But Stevens is not that far off. He’s undoubtedly entered the top tier of coaches across all of sports. So what would his value be in a hypothetical draft that included players, coaches, and general managers, with all salaries falling under the same salary cap?

I’d take Stevens over impressive young players like Jaylen Brown and Brandon Ingram, which means he’s ahead of high lottery picks. I’d take Stevens over the Jrue Holidays and Steven Adamses of the world, which automatically puts his value in the $20 million range. I’d take Stevens over aging stars like Chris Paul and injured ones like DeMarcus Cousins.

Obviously, players like LeBron James, Steph Curry, James Harden, Giannis, Anthony Davis, and Kevin Durant would be selected first. And rising stars like Embiid, Karl-Anthony Towns, and Simmons would go ahead of Stevens, too. But are you really taking DeMar DeRozan ahead of Stevens? I don’t think so.

It’s tough to know where to draw the line, but there’s no doubt Stevens has proved himself to be one of the most valuable commodities in the NBA. No matter whom the Celtics put on the floor, Stevens puts his team in positions to succeed. It’s why the Celtics, despite all the injuries they’ve suffered, are one win away from another conference finals. It’s why a series that once seemed like it would be another stepping stone for the up-and-coming Sixers hasn’t felt like much of a competition at all. Celtics-Sixers is officially a classic rivalry renewed, only right now Stevens gives the Celtics the upper hand.