Question: how many different march madness brackets are possible?
Answer: Virtually all bracket pools disregard these games and only have players pick from the first round, when 64 teams remain. Therefore, there are 63 games in a normal NCAA tournament bracket. As such, the number of possible outcomes for a bracket is 2^63, or 9,223,372,036,854,775,808. That's 9.2 quintillion.