Six years into his career, Irving has already claimed a place in the celebrated basketball lineage of smaller guards with outsized self-regard, his predecessors ranging from Earl Monroe to Allen Iverson. He hardly ever dunks, but he produces as many highlights as anyone. Irving’s tools are quickness, timing, a pool hustler’s sensitivity to angles, and a preternatural gift for dribbling. In the span of a couple seconds, he might move the ball from his right hand to his left and back again, start forward and retreat, and finally, having compromised his defender’s balance just enough, rise for a jumper or spin past him to the rim. In the paint, nobody in the world is better at lofting the ball off the backboard at Rube Goldberg trajectories, avoiding the long arms ready to block his shots.

For three seasons, that skill set made Irving a sometimes reluctant but often ideal running mate for James. When James drew the attention of the defense, Irving could catch a pass and knock down an open triple. When James got tired, Irving could run the show. Strain occasionally showed—after a reporter asked about James’s “parental role,” Irving rolled his eyes and said, “I have one father; that’s my dad, Drederick Irving”—but the relationship was at its best in the victorious seventh game of the 2016 Finals. James led the Cavaliers in points, assists, and blocks while playing all but one minute, and in the closing moments, Irving stepped up to make the title-sealing three-pointer. Instead of soaking up the adulation, in the confetti-strewn moments after the game, Irving redirected it to James, the Finals MVP. “I’m very thankful that I have a guy like that that’s leading our team that I can continue to learn from,” he said.

Irving’s present confidence that he’s learned enough is not wholly matched by the basketball intelligentsia. “He’s going to get you a lot of buckets, he’s going to score in the clutch, and he’s going to do a lot of things for you,” said the veteran reporter Howard Beck on the Lowe Post podcast, summarizing the opinions of executives he’d spoken with. “Is he going to be a great playmaker, defender, leader, all these other things that you usually want in that leading man? That’s the question.” Irving’s statistical output emphasizes the concerns. Though he averaged a career-best 25.2 points per game last season, good for 11th overall, his 5.8 assists were middling for a lead guard, and Basketball-Reference’s Win Shares—a statistic designed to pull together a player’s total contributions on both ends of the court—rated him as only the 23rd-most effective player in the NBA. The numbers merge the hesitation of league-wide higher-ups with the ethos of those mindbending YouTube clips: While Irving is a rare scorer and an overqualified sidekick, he may not function as a championship team’s engine.