Nope. I don't buy into it. If a team is playing better than they normally do, it is because of their abilities to perform at that higher level rather than fictitional description of the moment. I don't take issue with the use of the word momentum to describe these moments, but it isn't real. If a basketball team goes on a 12 point run after trading baskets for 5 minutes, it isn't a momentum shift. It's what you expect teams to do on occasion, because the game would be boring if both teams traded baskets an entire game. Skill, luck, focus, timing, exploiting the opposing teams weaknesses and toss in good coaching as the real reasons that teams can string together a mini-run or dominate the opposing team. Sports are a series of successes and failures. The team that succeeds more often will win more often. Momentum is just a feel good word to describe those successes.