Should we be upset about upsets?


Oh, the carnage: With upsets by Dayton and Connecticut, just 0.19 percent of the more than 11 million brackets in ESPN's Tournament Challenge called all of Saturday's NCAA games correctly. And then came Sunday, with wins by Stanford (picked by only 4.1 percent of entrants to reach the Sweet Sixteen), Tennessee (4.9 percent) and Kentucky (29.3 percent).

It's not just that there's nobody left with a perfect bracket, either at ESPN or in Warren Buffett's Quicken Loans Billion Dollar Bracket Challenge. Hardly anybody is even close.

To which statheads have this sophisticated response: Duh. A perfect bracket is virtually a mathematical impossibility -- and that's precisely the way the NCAA wants it.

There's a certain kind of awe in watching millions of people get wiped out of any contest so quickly, and it's fun to talk about how close you came (or didn't) to winning $1 billion. But as we all try to figure out how our predictions went wrong, keep this in mind: There's nothing magic about college basketball or this time of year that makes good teams prone to upsets by Cinderellas. Brackets get busted by something called the power of compounding.

Say you could pick the winner of NCAA games with 90 percent accuracy. You would have an 81 percent chance (0.90 x 0.90) of getting two games right, a 72.9 percent chance (0.90 x 0.90 x 0.90) of choosing three winners in a row, and so forth. With 32 games in the NCAA tournament's round of 64, your odds of selecting all of them correctly would be 0.90 to the 32nd power, or just 3.4 percent. That's just to get to the round of 32, and has nothing to do with which teams are playing. It's just the probability that something will run off the rails somewhere, even though there's only a 10 percent chance you will get any individual game wrong.

And of course, you probably can't choose games 90 percent accurately. The way the game of brackets is set up, there are just too many chances to go wrong.

Moreover, as the rounds progress, games get much harder to predict; you're faced with Iowa State-North Carolina instead of Wisconsin-American. So suppose you pick with 70 percent accuracy throughout the entire tournament. Your chances of selecting a perfect bracket would then be about one in 5.74 billion, which means the Tournament Challenge would have to run for more than 500 years before we could expect anyone to get all their games right.

The NCAA wants to get its most popular schools on network TV for as many games as possible while luring fans with unpredictability.

You might have seen even longer odds quoted, of 9.2 quintillion to one. That assumes every pick has just a 50 percent chance of being right. We'll say you're better than a coin flip.

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