This interview with the architecture critic Paul Goldberger on the ballpark is full of amazing insights, but this is my favorite:

In both time and space, [the game of baseball is] technically infinite. It’s the only major team sport that’s not played against the clock, and you don’t have goals at each end of a defined space the way you do on a football field or a soccer pitch or a basketball court or anything else. It’s very, very different the way it approaches the land, and the rules only lay out the diamond itself. The outfield could go forever, in theory. Of course, no outfield goes forever, the same way that no game really lasts forever, but the fact that the rules don’t specify either an ending in time or an ending in space makes baseball very, very different.