Why is the number so big? It’s pretty simple math. There are 2 possible outcomes for each game (win or lose) and there are 64 games as part of the tournament. That means that the total possible outcomes are 2x2x2x2…63 times (because all teams will lose at least one game except the winner of the last game, who is the champion). While multiplying a small number by 2 wouldn’t seem to create such a huge number, it does exactly that when done enough times. If you want to see how these odds are calculated, there is a great video below which explains it in a way that anyone can understand:

With the odds so stacked against you, why even bother to play? While there are a number of reasons that it’s worthwhile, there are two main ones that make participating worthwhile.

First, unlike the lottery, you don’t have to wager any of your own money to participate in this contest. If you had to pay to enter, it wouldn’t be worth your time or money. Since there is no cost involved in making the bracket picks, however, you aren’t risking anything but a little time.

Secondly, it’s not an all or nothing contest. If the contest were only the $1 billion prize or nothing, it would be questionable if even filling out the bracket would be worth the time. But this contest is offering more. The 20 best brackets will win a $100,000 prize put toward their current mortgage, or the buying of a new home. That means that there will be winners, and your guesses have just as much opportunity to be the best as the other people participating.

With that in mind, give the contest a shot. You risk none of you own money, and even though the odds are against you winning the top $1 billion prize, there is a chance for you to walk away $100,000 richer if you choose a great bracket.

People have been having fun with throwing out extremely low odds for getting all the teams correct and winning the billion dollars. Indeed, I’ve heard 9 quintillion to 1 (63 picks each 50:50). Better is to say you average a 2/3 chance each to get them all … this gives 124 billion to 1.

In big online bracket pools with upwards of 5M people, every so often there are maybe a couple people with a perfect Sweet 16 bracket … let’s say you get 10 such people in this Billion Dollar Challenge. And now, if you average a 2/3 chance of picking correct scores for the remaining 15 games, it’s 438 to 1 per person, so maybe 1 billion dollar winner every 44 years.

So the answer is somewhere between 1 in 44 and 1 in 8272 (124 billion / 15 million entries) that someone will win the pool depending on who you ask.

Your posit that there are almost always a few folks with a perfect sweet sixteen bracket ignores the premise of this challenge. You could have all 16 teams that are left which is impressive, but it doesn’t mean you picked the first 24 games correctly, you could do that by being correct on just 16 of those first 24 games. This challenge is a perfect bracket. 63 for 63. If all the one seeds are a shoe-in to win their first round game, your odds are still roughly 550 quadrillion to one.

Slight error. Although the odds ARE 1 in 9,223,372,036,854,775,808, the author says they are 9,223,372,036,854,775,808 to 1. If you’re going to put the odds in a ratio, then they are 9,223,372,036,854,775,807 to 1.

Just sayin’…

The other big flaw in your math is dividing 124 billion by 15 million. That would only work if all 15 million brackets entered in the contest were unique. In reality, there’s always going to be a ton of overlap, dramatically reducing the chances that Buffet ever pays that billion.

Winners of basketball brackett?