The Raptors are trying to reinvent themselves. A team that made a living on isolations and midrange jumpers is moving the ball and taking more 3s than ever before. Coach Dwane Casey has tweaked his playbook, but the bigger change has been in his rotation. Personnel dictates scheme in the NBA. The strengths and weaknesses of your players determine the system you can run. There’s a youth movement in Toronto behind the change in their style of play. The Raptors have one rookie and three second-year players in the rotation, all 23 or younger, and they have some of the best net ratings on the team:

The Raptors’ Core and Its Future, by Net Rating Player Age Net Rating Minutes Player Age Net Rating Minutes Kyle Lowry 31 Plus-4.1 686 DeMar DeRozan 28 Plus-4.3 720 Serge Ibaka 28 Plus-4.1 510 Jonas Valanciunas 25 Plus-0.1 345 Fred Van Vleet 23 Plus-20.4 341 Pascal Siakam 23 Plus-9.7 423 Jakob Poeltl 22 Plus-8.8 323 OG Anunoby 20 Plus-11.9 395

Most NBA teams count on their starters to win games and hope that their reserves can hold their own. Toronto is one of the few exceptions. It has a legitimate claim to being the deepest team in the league, with 12 players averaging at least 12 minutes per game, all of whom have played in at least 14 games. DeMar DeRozan and Kyle Lowry are the only ones averaging more than 27 minutes per game. Casey can mix and match between an almost infinite number of lineups. He has preferred having set roles for everyone in the rotation in the past, but his youngsters are playing so well that he’s had no choice but to find playing time for all of them.

Casey has already made one change from his starting lineup on opening night, swapping out Norman Powell for OG Anunoby, the no. 23 pick in this year’s draft. After starting the season 7–5, the Raptors have gone 7–2 since the move, including a dominating 129–113 win over the Rockets in Houston last month. Anunoby is averaging only 6.3 points, two rebounds, and one assist a game on 49 percent shooting, but his fingerprints are all over the game. Toronto’s original starting lineup had a net rating of minus-7.2 in 127 minutes this season. With Anunoby instead of Powell, they have a net rating of plus-2.7 in 124 minutes.

Anunoby is not playing like a rookie. He gets the toughest defensive assignment on the wings every night. In his first two weeks as a starter, he has guarded James Harden, Jrue Holiday, Bradley Beal, and Victor Oladipo. At 6-foot-8 and 235 pounds with a 7-foot-2.5 wingspan, he is a physical marvel who can match up with players at all five positions. He frustrated Harden and helped hold him to 8-of-25 shooting, picking him up full court and staying with him step for step. Anunoby has quick feet, long arms, and strong hands, and he knows how to use them:

Anunoby is more advanced defensively than most 20-year-olds because he had to earn playing time on that side of the ball early in his career. He was a complete unknown coming out of high school, not ranked in the top 250 in his senior class by the national recruiting services. Anunoby never really got the chance to be a featured player at Indiana, either. He was a defensive specialist as a freshman, and he tore his ACL only 16 games into his sophomore season before declaring for the draft. He slipped on draft night because it was unclear whether he would be healthy enough to play as a rookie, and no one quite knew what to expect out of him on offense. He was supposed to be a project.

The most surprising aspect of his play is his feel for the game. Anunoby is a developing shooter, but he’s able to contribute even on nights when his shot isn’t falling. He knows how to read the floor and react to what the defense is doing on the fly. He makes a shockingly low number of bad decisions for a young player: He shoots 62.2 percent from 2-point range, and he has an assist-to-turnover ratio of 2.5:1. Anunoby finds the open man when he has the ball:

The question for Casey is whether he needs to make more changes to his starting lineup. The combination of Jonas Valanciunas and Serge Ibaka up front is not working. The Raptors have a net rating of plus-0.5 in the 287 minutes the two have been on the floor this season, the worst of any of their top-21 two-man pairings in terms of minutes played. The two big men were even worse together last season, especially in the playoffs. Toronto began their series with Milwaukee and Cleveland starting both, and ended each with Valanciunas on the bench.

Supersized frontcourts like Valanciunas and Ibaka have a hard time keeping up with the increasing speed of the NBA game. The Bucks exposed them by trapping Lowry and DeRozan when they came off screens, forcing them to give up the ball and daring the Raptors big men to make plays in four-on-three situations, a role neither was comfortable in. Valanciunas is a deliberate player who likes to back down his opponents in the post, while Ibaka has never expanded his game beyond spotting up and making straight-line drives at the basket. The two combine to average only 1.3 assists per game, and it’s hard to run a ball-movement-heavy offense with two frontcourt players who can’t make plays.

At this stage in his career, Ibaka is more effective as a center. Playing at power forward means he has to spend most of the game chasing smaller players around the 3-point line. The position has changed around him. His block rates have gone down in each of the past five seasons because he’s spending less time near the rim. Nor does he get the chance to use his size much on offense. Ibaka has posted up 12 times this season, and he has only 15 offensive rebounds. When he’s playing at the 5, he can focus more on protecting the rim, and his ability to space the floor while guarding bigger players allows the Raptors to put more skilled and athletic players around him.

Casey is in a tough spot because of the financial commitments Toronto has made to Ibaka and Valanciunas. The Raptors will likely have both players on the hook for the next two seasons, and neither would be comfortable coming off the bench. The Raptors have been trying to trade Valanciunas for a while, but there’s not much of a market for a traditional center owed as much as $50 million, depending on whether he picks up his player option for 2019–20. There’s no urgency to make a move. Toronto is the no. 3 seed in the East, and they have the third-best net rating (plus-7.6) in the league. They could muddle through in the regular season without changing their lineup. However, if they fall behind in a playoff series, Casey will likely bench Valanciunas, just like he did last season.

He could go in a lot of different directions. The Raptors have more talented players than they can use. As Lucas Nogueira and Delon Wright sit out with injuries, Jakob Poeltl and Fred VanVleet have been able to step right in without missing a beat. Poeltl, the no. 9 pick in the 2016 draft, and VanVleet, an undrafted free agent from Wichita State whom they signed last season, have been plus-minus machines. Poeltl is a skilled 7-footer who can score and make plays out of the pick-and-roll, while VanVleet is a knockdown shooter who moves the ball and always seems to be in the right spot to make a play.

Their most interesting lineup might be putting a perimeter-oriented big man like Pascal Siakam, the no. 27 pick in the 2016 draft, next to Ibaka. At 6-foot-9 and 230 pounds with a 7-foot-3 wingspan, Siakam can play as a 4 or a small-ball 5, and he’s comfortable in a free-flowing offense. His assist rate (11.3 percent) is higher than Valanciunas and Ibaka’s combined. He’s not a good 3-point shooter, but it wouldn’t be hard to hide him in a lineup with so many other perimeter threats. On defense, he’s capable of switching screens and staying in front of smaller players, and he can block shots and compete on the boards:

The Raptors have been dominant in the 78 minutes that Anunoby and Siakam have played together, with a net rating of plus-22.6. Besides James Johnson, who never got out of Casey’s doghouse, they have never had players with their combination of size, skill, and athleticism. The Raptors need Siakam and Anunoby to match up with guys like Giannis Antetokounmpo, Ben Simmons, Jayson Tatum, and Jaylen Brown, not to mention LeBron James. Siakam and Anunoby can start at the 3 and the 4, and then slide to the 4 and the 5 against smaller lineups. A lineup with Siakam and Anunoby up front and either Powell or C.J. Miles on the wing would give DeRozan and Lowry more floor spacing and secondary playmaking to play with than they have ever had, without giving up anything on defense.

The Raptors have spent the past few years seemingly running in place. Like everyone else in the East, they have been playing in LeBron’s shadow, and they didn’t have the star power or perimeter athleticism to threaten him in a playoff series. Under the surface, though, they have been quietly retooling. They stole Anunoby, Siakam, and Powell in the draft, building an entirely different team around Lowry and DeRozan in the process. This is simultaneously the best and youngest group they have had in the past five seasons. Their transformation has just begun.