Golf could be in that many "big hitters" like John Daly can't sink key putts. In basketball one has to focus on the shot while airborne with another player obstructing your view. In baseball, will the pitch be a called strike three if you let it go; if you think so, where in the strike zone will it get to when? In hockey, sloppy puck handling can lead to the other team getting a good scoring chance. In football, a receiver has to focus on and catch a pass down the middle knowing a safety is about to unload on him as soon as he touches the ball. (And so on). So performing under pressure is what any competitive sport is all about.