It's not impossible to fill out a perfect March Madness bracket.
The odds are just terrible, though the exact odds are disputed. According to Forbes, you have a 1 in 9,223,372,036,854,777,808 chance of filling out a bracket without any errors. If it's easier to say, that's one in 9.2 quintillion.
One professor at DePaul goes as far as to believe the odds could be as good as one in 128 billion.
Watch his math and reasoning from 2012 below:
The data analysts at FiveThirtyEight assess the odds based off the fields. The odds of a perfect bracket in 2014 were one in 7,419,071,319, and they got better in 2015 with 1 in 1,610,543,269.
You have much better odds at being accepted into an Ivy League school or winning an Academy Award. Yes, the odds of becoming president are also better than predicting a perfect bracket.