“Wrestling the bear” isn’t quite as colorful a phrase as “jumping the shark.” But when you see Will Ferrell trying to fight a not-so-gentle Ben in his latest sports comedy, Semi-Pro, you can’t help but think the glory days of the former Saturday Night Live star’s dumb-guy shtick are over. Ferrell’s Jackie Moon, the dim-but-arrogant owner/coach/promoter/star of an American Basketball Association team in Michigan, is a lot like his Chazz Michael Michaels in last year’s Blades of Glory and Ricky Bobby in 2006’s Talladega Nights. But unlike both of those movies, which coasted on their one-joke premises amiably enough, Semi-Pro starts out promisingly and tanks fast. Worse, it doesn’t even have a solid golden gag to carry it. A two-dude figure-skating team? Comic genius. Ball players in the ’70s? Eh. The filmmakers—first-time director Kent Alterman and Starsky & Hutch writer Scot Armstrong—deserve some credit, however. The laughs that are there begin before we even catch a glimpse of the massively ’fro’d Jackie: The screen’s still fading into credits when we hear Ferrell whispering the filthy lyrics to “Love Me Sexy,” Jackie’s overexposed hit song that he refuses to let die. He’s singing it center-court before introducing his teammates with such give-it-up! descriptors as “He’s ugly as shit!” And on the sidelines are radio announcers played by Will Arnett and Andrew Daly, one lascivious and drunk, the other stick-up-his-ass squeaky. Good stuff. But once the story kicks in about the sorry team’s attempt to prove itself worthy of being absorbed into the NBA—a plot that introduces Woody Harrelson as a former Celtic who was traded for a washing machine—the shallow characters flatten completely and Semi-Pro becomes just another dull underdog movie. Two of the more ambitious comic set pieces, involving a gun and masturbation, go from mildly funny to wince-inducing and creepy, while the many cameos—except for Jackie Earle Haley as an “extremely dirty hippie” named Dukes—are as forgettable as Maura Tierney’s underwritten love interest. Ferrell still has great moments, pulling off an occasional brilliant delivery or affronted expression. But when you wrestle the bear, it’s time to move on.