B-

This movie about the unlikely pre-collegiate days of Baltimore Ravens football player Michael Oher, adapted by writer-director John Lee Hancock from the book by Michael Lewis, will strain your ability to suspend disbelief. Like all such glossy Hollywood versions of uplifting true stories, it’s frequently too slick for its own good, featuring big dramatic moments and funny interludes that often come across as contrived and prefabricated. Despite the title, you’re not going to feel blindsided by the plot turns; you’re going to anticipate them long ahead of time.

That said, despite its strong component of manipulation and its tendency to go for the emotional jugular, “The Blind Side” winds up working more than not, an old-fashioned crowd-pleaser that might just score a touchdown—although the lukewarm reception accorded to “The Express,” which was also a fact-based pigskin tale about triumphing over long odds, might suggest otherwise. Still, Hancock scored with “The Rookie,” another rose-colored sports tale drawn from real life. Maybe he can transfer his magic from the baseball diamond to the football field.

One thing that the movie definitely has going for it is that in the end there’s really not an awful lot of football action in the 128-minute running-time. To be sure, there’s game footage of Oher’s high school successes, but it’s situated within what’s overwhelmingly a human story of a young man with few if any prospects and the family that chooses to make him one of their own. And though Hancock doesn’t always avoid heavy-handedness in his treatment of the material, he’s blessed with a cast that keeps the film grounded in reality.

Most of the attention will probably go to Sandra Bullock, who stars as Leigh Anne Tuohy, the super-aggressive upper-class Memphis housewife who takes in Oher, the burly black kid from the wrong side of town who’s been accepted as a student at her children’s private school, partially as a charity case but also as a football prospect at the instance of Coach Cotton (Ray McKinnon). And in fact she’s quite good, even if the bossy, charge-ahead Southern belle she’s playing is more than a bit of a caricature.

But the person who holds the picture together is really Quinton Aaron, who plays the homeless, quiet, unassertive Oher—a gentle giant, to use the old phrase—with dignity, never losing the character’s melancholy thoughtfulness by turning him into a simpleton; he also manages Oher’s transformation to a more gregarious, outgoing person in the picture’s later stages. He even handles his big emotional moment, when he lashes out at a drug dealer and his posse, convincingly, and doesn’t overdo the jocular sequence when he shows a loquacious, and not a little racist, high school player on an opposing team who’s boss.

Among the others, Tim McGraw is excellent as Leigh Anne’s supportive husband, and Kathy Bates brings her patented brand of sass to the private tutor the Tuohys hire to help Oher. (She has one of the movie’s funniest lines when she confesses a secret about herself, which leads to another amusing observation from the Tuohys.) Hancock, however, might profitably have kept a tighter rein on young Jae Head, who plays the Tuohys’ young son SJ. He’s undoubtedly going to be an audience favorite, but the kid’s exuberance gets a mite exhausting—he’s playing to the rafters, and adds an unwelcome note of the sitcom to the proceedings. Adriane Lenox makes the most of her single scene as Oher’s drug-addicted mother, with whom Leigh Anne meets; it’s as eye-catching and moving a turn as the one Viola Davis gave in “Doubt” last year, and the result may well be the same when Oscar announcements come around.

Technically, “The Blind Side” is easy on the eye, with Alar Kivilo’s cinematography nicely substituting Atlanta locations for Memphis ones, the behind-the-scenes crew (production designer Michael Corenblith, art director Thomas Minton, set decorator Susan Benjamin and costume designer Daniel Orlandi) all doing solid work, and Mark Livolsi’s editing mostly crisp, although one suspects the running-time could have been snipped to under two hours. Carter Burwell’s score does what’s needed without being especially memorable.

A lot of real-life coaches show up in the final reels of “The Blind Side,” when Oher is being recruited by scores of colleges after his high-school success. It’s a stunt that will appeal to football fans, perhaps, but it actually undermines the veneer of authenticity that Hancock and his cohorts struggle to maintain because they’re stilted. Another miscalculation—one that’s become increasingly prevalent recently—is the decision to include file footage of the real Oher and the Tuohys during the final credits crawl. It’s a choice that never fails to subvert the sense of credibility the cast has worked so hard to create.

But even that misstep doesn’t undo the fine work that Bullock, Aaron and their colleagues do. This picture doesn’t have the grim reality of “Precious,” which tells a similar story in a far different—and frankly more powerful—way. But if you’re looking for an uplifting sports story, this one, familiar as it is, manages a winning score.