Question: how many possible combinations of ncaa tournament brackets?
Answer: 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. In case you were wondering, one quintillion is one billion billions. If we treated the odds for each game as a coin flip, that makes the odds of picking all 63 games correctly 1 in 9.2 quintillion.