Why do right hand batters hit the ball to left field percentage?

Don't know the percentages, but left field is more common. Most batters are right handed, and, on averge, a batter is more likely to "pull" the ball when he hits it. (Note: when a batter is said to "hit to the opposite field", that means that a right-handed batter hits to right field or a left-handed batter hits to left field. On the surface, this is not "opposite field" at all. But it's called "opposite field" because it goes against the natural tendency of a right hander to hit to left field and a left-hander to hit to right field.)