It's easy to argue against these things though. If a player can turn it up, why don't they do it all the time instead of only on selected occasions? Momentum - didn't Houston have all the momentum in the world after the first inning yesterday? We seem to have it now, but how confident are we that momentum will help Rick Porcello mow down the Houston hitters?
There's a lot of stuff in baseball that's just hard to explain. In the old days guys used to just shrug and say 'Hey, things just went my way today' or 'hey, I just didn't have it today'.