How many upsets will there be in the Round of 64? Prediction Market Analysis
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The best week on the sports calendar is finally here: The first 2 days of the NCAA Tournament.
In advance of tipoff on Thursday afternoon, I’ll be breaking down some intriguing Kalshi props in an effort to find value in the marketplace.
For this story, I’ll be breaking down a simple, yet complicated question: How many upsets will there be in the Round of 64?
Quick clarification right off the bat: In this case, “upset” refers to the seed line matchup. So a 9-seed who is favored in Vegas would still qualify as an upset for this market if it prevails over the 8-seed.
NCAA Tournament upset rate is a topic I wrote about in detail last week. Although there’s been plenty of commotion about the death of March Madness upsets following last year’s chalky tournament, I found that there’s no correlation between underdog performance in the regular season and the NCAA Tournament in a given year. So although the gap does seem to be widening between the sport’s top teams and its upset-minded minnows, that doesn’t mean March Madness upsets are going away.
With that being said, here’s how many seed-line upsets have happened in the Round of 64 in each of the last 10 NCAA Tournaments:
Round of 64 Upsets by Season
Number of times a higher-seeded team defeated a lower-seeded team in the first round
2020 tournament cancelled (COVID-19) | Upset = higher seed defeats lower seed
That’s a solid baseline. The mean is 9 and the median is 9.5.
Now, let’s get a little bit more precise. We can use money lines from sports betting apps to give us the implied probability that each underdog will win in the Round of 64.
I’ll spare you the long chart with 32 rows. After adjusting those odds to account for the sportsbooks’ margin (and using an approximate ML for the play-in games that aren’t finalized yet), the result is 6.86 expected upsets. Let’s round that up to 7.
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On Kalshi, 7+ upsets is priced at 51 cents per contract, so we’re pretty much exactly on market.
If markets are expecting 7 upsets on average, it sure looks to me like the tails (9+, 10+ or even 11+ upsets) are underpriced. Seven is the expected outcome based on the betting markets, but the range over the last decade swings from 5 to 13. That variance means we should see the upper end of the range more often than the 19 cent price suggests.
My baseline pick here will be to take 9+ upsets at 19 cents per contract. That’s close to 5-to-1 odds for what has historically been a median outcome. But I also really like the value of 11+ upsets at just 5 cents per contract. We’ve had 11+ upsets 3 times in the last 10 NCAA Tournaments, including once in the NIL era (2024).
Spenser is a news editor for Saturday Down South and covers college football across all Saturday Football brands.
