One-In-A-Billion March Madness Bracket Still Perfect Entering Sweet 16

Written By Eric Ramsey on March 25, 2019 - Last Updated on August 30, 2022

Ahhh, March Madness — the season in which your co-workers’ college basketball expertise is suddenly rivaled only by their confidence in filling out their bracket(s).

Opening weekend is a national holiday for bettors and water-cooler warriors, usually culminating in the ritualistic burning of said brackets. I introduced mine to a lit match by about dinner time on Thursday. Some of us don’t even have our Final Four teams still intact through the first four days of action.

There is one especially skilled picker on, however, who still has all 16 teams remaining. Not just that, this particular user has correctly picked all 48 games so far — not a blemish to be found on the sheet. It is an unprecedented, one-in-a-billion bracket.

Well… it’s not quite one in a billion.

Using betting data to calculate implied win probabilities, the odds of perfection through opening weekend are about 1 in 817 million.

The math behind a perfect bracket

If you were betting on flips of a coin (for some reason), the math is fairly straightforward.

With a fair coin, you have a 1-in-2 chance of winning a single flip, 1-in-4 of winning two in a row, and so on exponentially. Your odds of winning 48 consecutive coin flips are about 1 in 280 trillion.

Basketball games are not coin flips, though.

Calculating implied odds involves balancing the moneylines on each side of a game (from DraftKings Sportsbook), then multiplying the percentage for each correct pick. We also removed the operators’ vig to give us a better picture of the true odds.

That math gives our brave bracketeer just a 0.00000012 percent chance of perfection through the first two rounds — 1 in 816,927,896. For comparison, your odds of winning the Powerball jackpot are just better than 1 in 300 million.

This perfect-so-far bracket, by the way, has Gonzaga on the top line.

Perfection not without a few sweats

Despite all of the chalk dust, building the perfect bracket required picking a few big upsets and dodging some bullets along the way.

The betting odds show Liberty as the biggest upset on paper. The Flames closed at +280 for their first-round game against Mississippi State, giving them an implied win probability of barely 25 percent. Ohio State (30.42 percent), UC Irvine (31.46 percent) and Minnesota (33.64 percent) also won one game apiece as substantial underdogs.

A couple of big favorites made brackets sweat on the way to victory, too. Auburn (72.93 percent) gave New Mexico State a look at a game-winning shot on Thursday, and Tennessee (75.95 percent) needed overtime to beat Iowa despite a 25-point lead in the first half of their second-round game.

And, of course, Duke (88.64 percent) had serious trouble with UCF on Sunday night, escaping by just one point. For that matter, Virginia had the highest implied odds (96.63 percent) of the weekend, and even the ‘Hoos had to weather a threat from Gardner-Webb.

In the end though, the perfect bracket came out looking a lot like chalk. The favorites went 16-0 in the second round for the first time ever, and no winner had an implied percentage lower than 57.5 percent.

Check the odds for the Sweet 16 matchups here.

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