Sports betting on NCAA March Madness grows with historical underdog trends drawing wagers
Authored by zh-ayx-sports.com, Mar 18, 2026
The NCAA Division I men's basketball tournament, known as March Madness, engages millions of Americans through bracket pools, while legal sports betting volumes have risen sharply since the U.S. Supreme Court struck down the Professional and Amateur Sports Protection Act in 2018.
The American Gaming Association estimated legal wagers on the 2024 tournament at $3.6 billion, a 12% increase from 2023 and second only to the Super Bowl's $7.3 billion for Super Bowl LVIII.[1][2]
The event includes 68 teams playing 67 games from mid-March to early April, beginning with four play-in games among at-large and automatic-qualifier teams seeded 11 to 16, followed by the round of 64, round of 32, Sweet 16, Elite Eight, Final Four and championship.[3]
First-round upsets fuel betting interest. Entering the 2024 tournament, No. 12 seeds held a 20-140 record against No. 5 seeds (12.5% win rate), the highest among seeds 10 and below. No. 9 seeds led No. 8 seeds all-time at 69-87 (.442).[4][5]
Recent tournaments highlight potential value: since 2016, No. 9 seeds are 24-20 against No. 8 seeds (.545), offering near-even outcomes despite seeding.[4][5]
| Matchup | Lower seed wins-losses | Win % |
|---|---|---|
| No. 5 vs. No. 12 | 19-141 | 11.9% |
| No. 6 vs. No. 11 | 8-152 | 5.0% |
| No. 7 vs. No. 10 | 22-118 | 15.7% |
| No. 8 vs. No. 9 | 65-89 | 42.2% |
Bettors target these matchups for value against typical point spreads of 5-10 points favoring higher seeds, though favorites in extreme mismatches like No. 1 vs. 16 often see spreads widen.[4]
Oddsmakers report increased action on underdogs based on such trends, with notable past payouts from upsets like UMBC's 2018 win as a 16-seed over Virginia and Fairleigh Dickinson's 2023 victory as a 13-seed over Purdue.[3][4]
Sources
- American Gaming Association
Americans Expected to Bet $3.6B on 2024 NCAA March Madness Tournament, Up 12% From 2023
March 14, 2024
https://www.americangaming.org/press-release/americans-expected-to-bet-3-6b-on-2024-ncaa-march-madness-tournament-up-12-from-2023/ - American Gaming Association
Americans to Bet $7.3 Billion on Super Bowl LVIII, Up 45% from 2023 Super Bowl
February 9, 2024
https://www.americangaming.org/press-release/americans-to-bet-7-3-billion-on-super-bowl-lviii-up-45-from-2023-super-bowl/ - NCAA.com
What you need to know about the men's NCAA tournament
Accessed October 2024
https://www.ncaa.com/news/basketball-men/article/2024-03-17/what-ncaa-di-mens-basketball-tournament-records-get-broken-march-madness - CBS Sports
March Madness bracket: Records for every first-round matchup by seed
March 17, 2024
https://www.cbssports.com/college-basketball/news/march-madness-bracket-records-for-every-first-round-matchup-by-seed/ - ESPN
March Madness records: Biggest upsets, buzzer-beaters and more
March 20, 2024
https://www.espn.com/mens-college-basketball/story/_/id/39720086/ncaa-tournament-bracket-upsets-records-march-madness