On any ball hit to the right side of the infield, the pitcher must immediately move to cover first base. The path that the pitcher takes is to hit a spot near the baseline about ten feet in front of the bag--and then proceed up the line and through the base without crossing the baseline.
There are two reasons for taking this path. First, it avoids the possibility of a collision with the batter-runner. Second, it improves the angle at which the pitcher receives the toss from the first baseman--as the pitcher is moving more towards the first baseman rather than cutting away from him.
