It's a sport where pitchers who have an ERA or FIP of 3.5 instead of 4.0 are viewed very differently, where batters who hit .300 are viewed very differently than those who hit .275, where catchers who "call good games" are viewed very differently than those who "don't," where 20 home runs from SS is a great feat but 15 is commonplace, where an OBP of .330 is undesirable for a leadoff spot but .400 is elite, even though the difference is something like one time every 4 games. Discussions of players in 2013 revolve around the idea of replacement-level batters and pitchers, player value in terms of wins above replacement, and weighted stats that define not only what players are better or worse than their peers, but how much better or worse they are given the nature of what an average peer at a given point in time is doing. Upgrading from Ryan Ludwick to Matt Holliday would be a welcome one (given a salary and prospect neutral trade), even though the players have been very similar in recent years. Every bullpen transaction that doesn't involve fringe guys is based around marginal upgrades; Broxton replacing Arredondo as a RHSU was a large upgrade last year, even though they are reasonably similar guys.
If baseball wasn't won on the margins, the worst teams would lose 145 games and the best teams would win 145. The game is really, really, really hard and anyone can beat anyone on any given day. There is a minimum talent level that exists in baseball but doesn't exist in basketball or football.
And that's what makes baseball so special in my eyes.