Gom, instead of just doing it for runs or HR, they keep park factors for all types of stuff, know why? It's more than just where the fences are and how high they are. Those things are important, but so is prevailing wind, and often overlooked but very important, batter's eye. Don't quickly ignore the difference in parks, it's a factor in the outcome. For instance, over his entire MLB career, Dice holds batters to .100 less OPS on the road because Fenway is a good hitter's park.