But here's the issue: Is the slice you get off a right-handed bat to rightfield inherently different than the hook you get off a left-handed bat to rightfield? Seems to me that in each instance the bat will impart clockwise sidespin on the ball, causing it to tail toward the foulline. By the same token, both LH and RH hitters impart counterclockwise sidespin on balls they hit to LF. If I'm right about all of this, then there's no differentiating LF from RF on the basis of ball trajectory issues. Conversely, if hooking (pulled) balls behave differently (less tailing action, to be specific) than slicing (opposite field) balls, then your theory's got legs. Just a general observation, but I think everytime a LH batter hits a ball the spin will be counter clockwise, and RH batters will always generate a clockwise spin. A pulled, hard hit would generate less spin, but not a reverse spin. I could be wrong, but I can't picture a situation where a RH batter hits a ball that generates counterclockwise spin. Theoretically, a circle-change or a screwball which have clockwise spins approaching home plate would conceivably cause this. A 10-4 curveball delivered by a left-hander would do this as well, to a lesser extent.