Variance is definitely part of the equation, but its substantialness is overestimated. I think most would agree that process is more important than product when looking at individual events. It's the frequency of the event that is most important. Putting the bat on the ball is an important skill. Throwing strikes in the zone that are more likely to induce weak contact or no contact is an important skill. Having great hand-eye coordination is an important skill. When all those things come together more times than not, variance is going to be in favor of whoever can do those things best.