What are the True Odds of a Perfect Bracket?

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.

Thursday

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:

ICYMI: Biggest tourney upsets since 2005 Norfolk +2250 v Mizzou (’12) UAB +991 v ISU (’15) Ohio +925 v GTown (’10) Mercer +843 v Duke (’14)

— SportsInsights.com (@SportsInsights) March 19, 2015

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.

Of the 11.57 million brackets entered in ESPN’S Bracket Challenge, ONLY 273 are perfect. Last year, there were 18,471 correct after day 1. — SportsCenter (@SportsCenter) March 20, 2015

Friday

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.

Out of more than 11.57 million brackets entered in ESPN’s Tournament Challenge, 1 perfect bracket remains. This one: http://t.co/Bzk4VyUTVo

— David Payne Purdum (@DavidPurdum) March 21, 2015

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.

Saturday

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.

Sunday

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.