For example, "Andre was really into batting and doing it himself," says Sea Level effects supervisor Dan Connelly. "They did have him do it a bunch of times, but when it came down to it, he could get his most powerful and confident-looking swing when he wasn't swinging at a ball that someone was throwing at him at 100 miles per hour." Because of that, Agassi pantomimed the swing, and Inferno artists animated the ball into the shot, as they did with Williams' volleyball and Vick's puck. The desired look was one that is virtually indistinguishable from a highlight reel, but creatives didn't want to do a simple composite job for each scene. "We wanted to do the effects in as many different ways as possible so there isn't one technique that you pick up on in the first shot and you're just watching for that the whole time," Connelly says.
Each scene takes inspiration from a piece of stock footage and employs such tactics as head replacement, greenscreen background compositing, body doubles, morphing and animation. Some shots used recreated reaction footage live, and others were thick with effects. In Armstrong's boxing match, the cyclist squared off against a stock fighter, following choreography and hitting targets in front of a greenscreen at the live shoot. In Agassi's scene, his face was applied to the body of a shortstop filmed by Johansson making a particularly awe-inspiring play. In tighter scenes, Agassi swung the bat in front of a greenscreen, and crew members recreated the Fenway Park dugout. For Marion Jones' vault, Connelly and company used a gymnast body double to judge how someone Jones' size would articulate the stunt, then had Jones perform various phases of the move and morphed the two with the gymnast in the stock footage.