What are the True Odds of a Perfect Bracket?

The first week of the NCAA Tournament is behind us and most bettors are already looking forward to the Sweet 16 and Elite 8. However, with all the talk of improbable upsets and Cinderella stories, we wanted to know how unlikely the events of the past week were. There’s not a single perfect bracket in the country, but we wanted to know the real probability of boasting a flawless bracket.

In order to accomplish this, we broke down the moneyline for the winning team on each of the first four days of the tournament. By converting these moneylines into an implied probability, we were able to determine the estimated odds of perfection for every day of the tournament.

It’s worth noting that we used closing lines from Pinnacle and that our implied odds account for juice, meaning that the actual probability for all of these figures would be slightly higher.


Winner Loser Winning ML Implied Odds
Kentucky Hampton -50000 99.80%
Arizona Texas Southern -7000 98.59%
Villanova Lafayette -6000 98.36%
Notre Dame Northeastern -1000 90.91%
North Carolina Harvard -525 84.00%
Georgetown Eastern Washington -375 78.95%
Arkansas Wofford -320 76.19%
Utah Stephen F Austin -304 75.25%
Ohio State VCU -168 62.69%
Texas Butler -145 59.18%
NC State LSU -137 57.81%
Xavier Mississippi -130 56.52%
Cincinnati Purdue -123 55.16%
UCLA SMU +156 39.06%
Georgia State Baylor +393 20.28%
UAB Iowa State +991 9.17%

Although there were only three moneyline upsets on the first day of the tournament, UAB’s upset was one of the most improbable wins in our database. In fact, since 2005 UAB was the second biggest moneyline underdog to win a tournament game:

For what it’s worth, the odds of hitting a 16-team parlay with all of these teams would be +624,694 meaning a $100 parlay would pay out $624,694 (assuming you could find a sportsbook to take this bet and that doesn’t have a payout limit). When we multiply these implied odds together, we find that the probability of having a perfect bracket after day one was just 0.016248% — or roughly 1 in 6,154. 

This year there were over 11.5 million brackets submitted into ESPN’s bracket challenge. Based on these numbers there should have been about 1,868 perfect brackets after the first day, but that figure turned out to be significantly lower.


Winner Loser Winning ML Implied Odds
Duke Robert Morris -7000 98.59%
Wisconsin Coastal Carolina -4800 97.96%
Gonzaga North Dakota State -2700 96.43%
Virginia Belmont -2700 96.43%
Oklahoma Albany -1100 91.67%
Kansas New Mexico State -550 84.62%
Louisville Cal Irvine -460 82.14%
Northern Iowa Wyoming -300 75.00%
Wichita State Indiana -280 73.69%
Georgia Michigan State -255 71.83%
Maryland Valparaiso -235 70.15%
West Virginia Buffalo -215 68.25%
San Diego State St. John's -201 66.78%
Iowa Davidson -142 58.68%
Oregon Oklahoma State -103 50.74%
Dayton Providence +126 44.25%

Friday was a great day for bettors who took chalk, as 14 of 16 favorites won straight up. The most notable exception was the final game of the night with 11-seeded Dayton (+126) upsetting 6-seeded Providence. The only other upset — and I used that term quite loosely — was 8-seed Oregon (+1) knocking off 9-seed Oklahoma State.

Even with almost every favorite advancing through to the Round of 32, the implied odds of picking all 16 games on Friday were 0.9569% — or roughly 1 in 105. When we multiply the odds of posting a perfect bracket on both Thursday and Friday, we get 0.000001554773% which works out to 1 in 643,181.

With 11.57 million brackets submitted, we could have expected around 18 perfect brackets. It turns out that only one bracket remained perfect after the first two days of the tournament.

One of the reasons for these lower numbers is that so many submissions likely picked the same trendy upset picks.  For example, if the upsets had been the 12-seeds over the 5-seeds instead of the 14-seeds over the 3-seeds, the implied probability wouldn’t have varied greatly, but more brackets would have picked them based on public perception and previous years’ results.


Winner Loser Winning ML Implied Odds
Kentucky Cincinnati -2300 95.83%
Arizona Ohio State -575 85.19%
Xavier Georgia State -260 72.22%
UCLA UAB -230 69.70%
North Carolina Arkansas -230 69.70%
Utah Georgetown -190 65.52%
Notre Dame Butler -184 64.79%
NC State Villanova +464 17.73%

Although the 8-seed NC State (+464) was able to knock off 1-seed Villanova, the rest of Saturday’s games went largely as expected. Assuming you already had a flawless bracket through two days, the odds of continuing perfection on Saturday would have been 2.16%. When we encompass our odds from the first two days, we see that the odds of picking every game correctly though three days would have been 1 in 2,983,522,098.


Winner Loser Winning ML Implied Odds
Wisconsin Oregon -1100 91.67%
Duke San Diego State -585 85.40%
Gonzaga Iowa -285 74.02%
Oklahoma Dayton -198 66.44%
Louisville Northern Iowa -140 58.33%
West Virginia Maryland -126 55.75%
Wichita State Kansas -102 50.49%
Michigan State Virginia +184 35.21%

There were technically two upsets on Sunday, though it’s tough to consider Wichita State a true Cinderella story since they closed as only 1-point underdogs. The only true upset was 7-seed Michigan State (+184) knocking off 2-seed Virginia. Based on our implied odds, the probability of picking a perfect bracket on Sunday would have been 2.23%.

When we multiply the probability of picking the first three days correctly with the odds of picking all of Sunday’s games correctly we find just a 0.0000000000007709% chance of picking a perfect bracket thus far. That translates to approximately 1 in 1,297,183,520,869 (about 1.3 trillion).

If you were just randomly picking games (by flipping a coin for example) then your odds of being perfect heading into the Sweet 16 are roughly 1 in 281.5 trillion.

Getting ready for this week’s slate of games? Make sure to bookmark out free College Basketball odds page for the latest lines and public betting trends.

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David Solar

David Solar is the Content Manager at Sports Insights. He specializes in sports betting analytics and creating data-driven betting systems. He can be reached directly at david@sportsinsights.com or on twitter at @TheDavidSolar.

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