Because momentum isn't real. It's just a word people use to define the moment. I'll buy that. What I don't buy is it's real with other sports, but not with baseball. I've been checking out case studies on the web and to some extent it's real, but the studies always come up inconclusive or not enough evidence. Do you not at all buy the argument that, if you choose define momentum as something that inspires or "pumps up" players (that's the only way I can see momentum being looked at as something remotely tangible), allowing them to play at a higher level, it is something that can be helpful in a game like, say, football or basketball, but not so much in baseball? I see some validity to it. If a player's adrenaline is pumping in football (it damn well better be) or basketball, the players can run faster, hit harder, jump higher, etc. In baseball, being pumped up doesn't seem like it would help a player much. It can cause a pitcher to overthrow and leave balls up. It can cause hitters to try to swing harder than they normally would (usually not a good thing) and swing at pitches that they normally wouldn't. To me, it's pretty obvious that those other sports are more conducive to the idea of something like momentum than baseball. There are too many variables, and there's too much finesse to the game in comparison to the others. Wouldn't that be adrenaline? This is how I would define Momentum in sports: Couldn't this definition of Momentum in sports be applied to all sports? Being "pumped up" applies to all of these things (the bolded). It could also be negative, one bad play snowballing into another, etc. I'd tend to say there's more validity to the idea that negative momentum exists in baseball than positive. A player can easily cause negative outcomes to happen in baseball without the assistance of other variables. i.e. it's a lot easier to see a player going up to the plate pissed off, going through the motions, and striking out than it would be to imagine that he'd go up there and get a hit somehow as a result of his positive "momentum." So...maybe I buy the idea of negative momentum, to some extent. But I can't really see positive momentum existing to a significant extent in baseball.