You only think you're following the ball in.

This article busted this myth back in 1954. Yet, the myth still grows. This is based on the concept of Angular Velocity.

The truth is that baseball hitters never do see the ball when they swing at it. They lose sight of it anywhere from eight to 15 feet away from home plate.

A recent article summarizing recent studies

First, they might follow the path of the ball for 70-80% of its flight, but then their eyes can't keep up and they estimate or extrapolate the remaining path and make a guess as to where they need to swing to have the bat meet the ball. In this case, they don't actually "see" the bat hit the ball.

Second, they might follow the initial flight of the ball, estimate its path, then shift their eyes to the anticipated point where the ball crosses the plate to, hopefully, see their bat hit the ball.

This inability to see the entire flight of the ball to contact point is what gives the pitcher the opportunity to fool the batter with the speed of the pitch [editor: or via a late or unexpected break].

If a hitter is thinking "fast ball", their brain will be biased towards completing the estimated path across the plate at a higher elevation and they will aim their swing there. If the pitcher actually throws a curve or change-up, the speed will be slower and the path of the ball will result in a lower elevation when it crosses the plate, thus fooling the hitter.

Angular Velocity also explains why MLB hitters can't hit Jenny Finch without practice. MLB hitters are very good at predicting the expected path of 2 seam fastballs and baseball curveballs. But, they can't predict the path of a softball pitch, without practice.

Of course, fastpitch hitters couldn't hit a baseball pitcher either - without practice.