The Big Mo' - Momentum In Sports

A player can feel it during a game when they hit a game-changing home run or when they go 0 for 4 at the plate. A team can feel it when they come back from a deficit late in the game or when their lead in the division vanishes. A fan can feel it as their team "catches fire" or goes "as cold as ice". And, play-by-play announcers love to talk about it. We know it as the "Big Mo", the "Hot Hand", and being "In The Zone" while the psychologists call it Psychological Momentum. But, does it really exist? Is it just a temporary shift in confidence and mood or does it actually change the outcome of a game or a season? As expected, there are lots of opinions available.