Did Villanova, Louisville or Duke ruin your dreams of predicting the perfect NCAA tournament bracket this weekend? Of course they did, but at least my bracket in my pool survived. Well, sites like ESPN offer a second chance, to predict the tournament from the Sweet 16 onwards so feel free to try again. However, what is the actual probability of predicting a perfect full bracket? Well, your chances of winning the lottery are much higher.

Let me show you a simpler version of the calculations by just looking at the Final Four. Given which teams make this round, how many different ways can the remainder of the tournament pan out? There are only two possible outcomes for each game and the Final Four consists of two games. Because your selections for these games determine your options for the third game (title game), you’re basically trying to predict three games correctly. 2³ = 8. That leaves eight different choices you can make.

Now let's look at the full 64-team NCAA tournament since it's formatted the same way throughout (the men’s tournament really has 68, but 4 get eliminated by the time most bracket contests start). The rule of thumb under this tournament's format is the total number of games is one less than the total number of teams. So you have to predict 63 games correctly. 2⁶³ = 9,223,372,036,854,775,808. Okay, in case you’re wondering just how big that number is, it has 19 figures, with the "9" in what's called the quintillions place. There are over 9 quintillion different combinations to fill out the bracket. As you probably figured, there’s effectively 0% chance of hitting a perfect bracket by just guessing.

But, those who follow basketball would know a 15-seed rarely beats a 2-seed & a 16-seed has never beaten a 1-seed (at least in the men’s tournament). Your chances improve, but remain miniscule. Assume all teams seeded 1-4 (16 teams) get to the Sweet 16, winning two games each. Hypothetically given the results of these 32 games, that leaves 31 left to predict. 2³¹ = 2,147,483,648. With 1 / 2,147,483,648 odds, if everybody in America (324,420,000 residents) submits a bracket under these conditions, then the probability that a single bracket will be perfect is barely over 15%. Yet, that’s generous; DePaul professor Jeff Bergen estimated that knowing basketball would leave about 128 billion possibilities open, closer to 2³⁹ which assumes results of just 24 games. With that many possibilities, the probability of any American getting a perfect bracket drops to barely over 0.25%.

Jealous that your friend's bracket hasn't gone up in smoke like yours? Remember, it will, soon enough.