Everyone’s favorite thing about betting on March Madness is the upsets — or “bracket busters” as they’re famously called. For bettors or bracket pickers, upsets quite literally make or break their NCAA Tournament predictions. Being on the right end of an upset is euphoric, but if on the opposite side, one is sort of crushed but also sort of happy in a sly way. Happy because you can’t help but grin at these unpredictable moments.

As you prepare for the upcoming March Madness tournament, we felt obliged to create an entire guide to tournament upsets. How they happen historically and what you can do to end up on the right side of an upset this year while picking games. There’s a lot to cover so let’s jump right into it:

March Madness Upsets By The Numbers

Thankfully, we don’t have to completely guess when it comes to upsets. Why? Because we have decades worth of data to clue us in on the most likely upsets March Madness that occur.

We’re now entering year 40 when the NCAA basketball tournament expanded to 64 teams (and 63 games total). Technically, we’re at 68 teams and 67 games now thanks to the inclusion of play-in games, but for the basis of this article, we’ll disregard these. We’re strictly measuring first-round results since 1985 when the NCAA expanded to the format we see today. Here’s what the data tells us:

No. 1 vs. No. 16 (150-2 record)

Upsets don’t get any bigger than this. Luckily for us, we’ve witnessed two of these bracket-busters in recent memory. First, there was UMBC knocking odd Virginia in 2018. Then even more recently, FDU shocked Purdue in 2023.

Both those moments were historic but rare. The record speaks for itself — No. 1’s have won 150 out of 152 possible games. Therefore, picking bracket-busters here isn’t advisable.

No. 2 vs. No. 15 (141-11 record)

In 2023, No. 15-seeded Princeton sent No. 2 Arizona packing in another stunner. This became only the 11th instance in 152 games where the first-round upset happened. So as you can tell, it’s probably not a round where you should be betting bracket buster either as it remains a pretty low probability at online sportsbooks.

No. 3 vs. No. 14 (130-22 record)

All right, you can see the odds of an upset slowly creeping up. Based on the all-time record, the chances of a No. 3 being upset in the opening round is double that of a No. 2. Regardless, these upsets only happen 15 percent of the time so the overall likelihood remains marginal.

No. 4 vs. No. 13 (120-32 record)

Seventy-nine percent of the time in this matchup, the higher seed wins. As you’re seeing, you can slowly start contemplating upsets the further along you go, but it’s still a high-risk bet with the top four seed games.

No. 5 vs. No. 12 (99-53)

All right, this is the round where upsets start becoming a lot more common. The lower seeds have a win percentage of about 35. Those chances are worth taking if you can find a sneaky good No. 15 team (more on that later).

No. 6 vs. No. 11 (94-58)

This isn’t as “sexy” or an upset as No. 5 vs. No. 12 because the seeding is now getting close. However, no surprise, this upset is much more likely to happen.

No. 7 vs. No. 10 (92-60)

Is this even considered an upset? Probably not. It’s not uncommon to start seeing the lower-seeded teams have better moneylines to win — usually when a powerhouse school plays a mid-major that won their conference.

No. 8 vs. No. 9 (74-78)

This one for sure isn’t an upset. Matter of fact, this game is routinely the hardest to pick. As it stands, the lower seed has a slight head-to-head advantage.

How To Find A “Cinderella Team”

Now that you have concrete data that tells you where upsets are likely to occur, how do you actually go about finding an upset-worthy team? Or better yet, a “Cinderella story” that goes deep into the tourney as a low seed? This isn’t a perfect science, but here are a few tried-and-true qualities of low-seeded teams that end up making a run:

Streaky play: there’s a famous saying that goes “ride the hot hand.” That couldn’t be more accurate when describing Cinderella teams. Many times, these schools enter the bracket on a hot streak and use that momentum to propel them forward. So look out for a team that's on a big win streak or just tore through their conference tournament.

Elite offense: Cinderellas very often can score with the best of ‘em, including those top seeds. One of the most famous upset stories in tourney history happened in 2008 with No. 10-seeded Davidson, led by Steph Curry. Him, and that team as a whole, could light up a scoreboard on any given night — a quality that works wonders in March.

Non-conference strength of schedule: the majority of Cinderellas are mid-majors. These teams can be hard to gauge because the less-than-stellar connection they often face in their conferences. However, if you see this team has competed and beat Power-5 teams in nonconference battles, then they have Cinderella written all over them.

Meet the author

Eric Uribe

Eric has been passionate about sports since he was 10 years old. He brings over 10 years of sports journalism experience to his expert coverage of sports betting. Hailing from the US, Eric leverages his diverse expertise covering sports at all levels – from high sch...