Inspiration obviously comes from a variety of sources, but Uncle Drew doesn't have the most promising of origins. It's a concept introduced in 2012 with a series of Pepsi television commercials that cast NBA All-Star Kyrie Irving as a bearded old man who shocks and delights blacktop spectators by showing up his young competition with his improbably dynamic basketball play. That's really all there was to it: Irving, looking more like a present-day Bill Russell, shooting, dunking, and breaking ankles like no old-timer ever has.

Not since Jim Varney's Ernest P. Worrell lept from local ads to a series of critically lambasted but somewhat beloved movies has this been done before with any success. And yet Uncle Drew pulls it off, its boilerplate narrative bolstered by a fun cast and enough wit to render it consistently entertaining from start to finish.

Though Drew gets the title and Irving top billing, the real protagonist of the film is Dax (Lil Rey Howery, Get Out's scene-stealing TSA agent), a coach whose prospects in the annual Rucker Park streetball tournament look good based entirely on the skills of Casper (Aaron Gordon, the Orlando Magic's starting power forward in real life). But Dax has demons in the form of one Mookie (Nick Kroll), a trash-talking repeat champion who has been in Dax's head since blocking his shot in a big game as children. Mookie's team has won seven of the last nine years, but Dax thinks he can beat them and the cash prize would certainly improve his financial status as a Foot Locker salesman and at least temporarily appease his materialistic girlfriend Jess (Tiffany Haddish, Girls Trip). Instead, Mookie poaches Casper and after Jess kicks out Dax, the nemesis moves in on her too.

Who can save Dax, who already has invested the little he has in entrance fees and suddenly finds himself without a team? Why, Uncle Drew, of course. The legend's virtues are extolled in the opening scene's ESPN "30 for 30" mockumentary clips with commentary from real Rucker Park alumni and NBA Hall of Famers including Dikembe Mutombo and Bill Walton. The stories are also on the lips at the barbershop (which employs aged, made-up J.B. Smoove and Mike Epps). But it's not until Dax sees Drew show up some headstrong young ballers that he is hooked.

The two hop in the septuagenarian's funky, impossibly well-preserved 1970s van in order to reassemble Dax's old Rucker Classic squad, which had a falling out decades ago over Drew sleeping with a teammate's girl on the eve of a championship. At this point, Uncle Drew takes the shape of an episodic road trip comedy as the old 8-track enthusiast reunites with his boys: feathery-haired D.C. preacher Preacher (Chris Webber), now-blind former sharpshooter Lights (Reggie Miller), the traumatized Boots (Nate Robinson), who is mute and immobile in a retirement home; and Big Fella (Shaquille O'Neal), who teaches karate to children while looking "like Wolverine's grandfather."

These men are old and in no shape to play, let alone win, something Dax quickly realizes. Of course, things aren't as dire as they seem and eventually we do come to the tournament in which the outcome is not much in doubt for us.

Written by editor turned scribe Jay Longino (the 2016 Jackie Chan-Johnny Knoxville vehicle Skiptrace), Uncle Drew doesn't break any molds or shock us narratively. It hits all the beats you would expect and largely in a manner you might predict. But it has an awful lot of fun doing it and entertains without making you cringe. From a distance, this looks like a Tyler Perry comedy: broad characterizations and some heavy aged make-up. But it's never as lowbrow as you almost expect a movie based on Pepsi commercials to be. And the cast proves to be enjoyable and more appealing than you expect a cast heavy on professional athletes to be. Howery is a likable presence who shines in the spotlight. Irving succeeds by underplaying the title role. His retired castmates go a lot bigger, but for the most part succeed, with only Miller and occasionally Webber going too big.

Whether Longino wrote them or they were improvised, the film is peppered with little jokes that will land big with those who get them, from a shot at Kobe and an hilarious reference to Webber's infamous Final Four timeout gaffe to a generational mix-up of Notorious B.I.G. and The Isley Brothers that brought down the house with my enthusiastic and vocal screening crowd.

High art, Uncle Drew is not. Quality entertainment, it is. It hits way more of its shots than it misses and even if it's as formulaic as can be, it still emerges as the best basketball movie since Space Jam.