Clifton Collins, Jr., the star of the racetrack drama "Jockey," has riding in his blood, although the skill is so rarely called for that we've almost never gotten to see him do it. Born Clifton Gonzalez Gonzalez, Collins is the grandson of one Western movie and TV actor, Pedro Gonzalez Gonzalez, and the grand-nephew of another, Jose Gonzales-Gonzales. Collins played a small role in the Western scenes of "Once Upon a Time in Hollywood" and as of this writing was a regular on "Westworld." His "Jockey" character, veteran rider Jackson Silva, was created by the film's co-writer and first-time director, Clint Bentley, who grew up around horse tracks because his own dad was a jockey. This background information is by way of explaining what you're getting yourself into when you watch "Jockey": a film that doesn't have much plot to speak of, that plunges you into the middle of a richly detailed world built from firsthand observations, and that unifies itself around the teamwork of Bentley and Collins. Theirs is an indie-film mind meld for the ages, on par with the work Abel Ferrara and Willem Dafoe have been doing since Ferrara got sober. Collins is convincing from frame one. When seen in silhouette (which is often) he has the sinewy outline of a rodeo rider or caballero from old movies where men slouched with a cigarette or blade of grass between their teeth. He radiates the steely competence that Steve McQueen brought to Western dramas like "Nevada Smith," "Junior Bonner" and "Tom Horn." Jackson is an experienced rider nearing the end of his career. He's macho but easygoing. He doesn't puff his chest out trying to impress anyone, because that kind of preening calls down trouble, and he's got enough anxiety to contend with. There are not a lot of surprises to be found in terms of story: there's a horse trainer named Ruth ("Deadwood" star Molly Parker) who's been Jackson's friend for years and seems as if she might be inclined to move things into a different category. And there's a young new guy named Gabriel (Moisés Arias) hanging around the track. He's about the right size to be a jockey. He eventually admits he's been following Jackson around the riding circuit to stay close to him because (he says) he's the product of a fling Jackson had with a woman 19 years earlier and believes it's his destiny to join his dad's world.