DESPERATELY SEEKING CINDERELLA

Last year was a bad tourney to be a low-seeded underdog. Unlike 2006, when eleventh-seeded George Mason made its historic run to the Final Four, 2007 produced only three modest upsets. That was easily the lowest number of Cinderella surprises in the 23 years of the 64/65-team era. But if you think that 2008 will be a “by-the-numbers” repeat of last year, think again.

Conditions are ripe for another tourney of double-digit upsets—and your bracket pool will likely be won by the person who can identify the right favorites to fail and longshots to advance. Of course, Cinderella spotting is tricky business. Settle on the wrong high-seeded victim and your bracket could collapse in the first weekend.

Fortunately, picking the right underdog isn't all guesswork. The Cinderella squads of the modern era have shared common attributes. When you know what they are, it's a lot easier to sniff out the upsets. Let's examine the factors that correlate with upsets and identify the darkhorses in this year's bracket that have the right statistical stuff to spring a surprise.

When is a win an upset?

Not every game in which a lower-seeded team knocks off a higher seed is an upset. Nobody's going to fit a glass slipper on a ninth seed that beats an eighth seed in round one. (Actually, No. 9 seeds are 50-42 against their higher-seeded opponents.) It's only when you get a gap of at least four seed positions between opponents that a game has upset potential.

Surprisingly, two-thirds of tourney games meet this condition. Of the 1,449 games that have been played in the last 23 years, 967 of them have pitted longshots against favorites—and the underdog has won about 20 percent of the time. That's an average of 8.5 upsets per tourney, or roughly one in every seven games. (Now you know why 2007’s total of three upsets was so unusual.) This chart shows the round-by-round results of upset games…