Let's look at this from the prospective of pitching. Pitching coaches encourage pitchers to leap out as far as possible, to get right on top of the hitter. I have never heard a pitching coach say that spin pitches are more effective if you stay as far away from the hitter as possible to give the ball more distance to break. Moving the pitching rubber 3 ft further away from plate must have really helped pitchers and hurt hitters.