As far as what-if scenarios go, “Grudge Match” floats one that’s hard to beat: What if Rocky Balboa fought Jake LaMotta?
Though Sylvester Stallone and Robert De Niro are hardly doing an exact reprise of their pugilist icons from “Rocky” and “Raging Bull” here, even faintly suggesting this fantasy bout has novelty value. There’s also value in the oddity of seeing these two stars work together, although Stallone’s “Expendables” spotlight-sharing and De Niro’s increasingly undiscriminating tastes make this seem like casting we should’ve seen coming.
It’s also a match-up that comes about three decades late. Director Peter Segal (2005’s “The Longest Yard”) and his writers get this, and they actively acknowledge it through their characters’ skepticism about bringing closure to a “Fight That Never Was.” But that presents a big task: projecting freshness when so much is self-deprecatingly made of how creaky this all is.
In an opener that cleverly repurposes “Rocky” and “Raging Bull” footage, we learn that Henry “Razor” Sharp (Stallone) and Billy “The Kid” McDonnen (De Niro) are Pittsburgh-bred archrivals who split a pair of epic fights in the ’80s. They were headed for a decisive third contest when Razor abruptly quit the sport. Fast-forward all those years, and unassuming Razor is a mill worker still ducking why’d-ya-do-it questions from buddies and his cantankerous trainer (Alan Arkin, giving Burgess Meredith a mischievous streak and a potty mouth). Unrepentant party guy Kid has done better, putting his money into a restaurant where he’s fawned over by nostalgists and does stand-up as awful as LaMotta’s. But it’s clear it still eats at him that he never got another shot at his nemesis.
Enter a wannabe promoter (Kevin Hart, verbally sprinting as always) with a pitch to have the two square off as video game characters. (Wasn’t that a plot point in “Rocky VI”?) When their confrontational game-recording session — in motion-capture unitards! — blows up on YouTube, they’re on their way to getting back in the ring for real. Creakily, of course, and with some misgivings about the cholesterol risk of egg-chugging. Razor soon reconnects with his long-lost true love (Kim Basinger, passable but still no comedienne). In a forced story thread, Kid meets the adult son he’s never known (Jon Bernthal). And eventually, we do get an intriguing answer to that early-retirement mystery.
Still, most are likely here for the sport far more than for drama in the “yo, Adrian” vein. But we can only get so fired up for a showdown between aging characters whose commitment and scorn come and go, and featuring actors content to play it that way, however game they are to get physical. Stallone and De Niro simply don’t generate enough combative spark to make this anything more than an amiably mediocre diversion.