Every March, 68 American college basketball teams enter a winner-takes-all tournament that stretches across three weeks and regularly produces some of the most dramatic upsets in sport. It's called March Madness, and the name fits. A 16-seed knocking off a No. 1. Buzzer-beaters that end seasons. An entire nation filling out brackets and losing their minds.
March Madness can be a very interesting event to consider when it comes to finding value and 'unusual' betting opportunities, but it helps to understand the machinery behind it first.
The format, the seedings, how teams qualify, and why underdogs win more often than you'd expect. This guide breaks all of that down. For the latest odds, schedule in AEST, and betting tips, check out our March Madness 2026 betting guide.
What Is the NCAA and College Basketball?
The NCAA (National Collegiate Athletic Association) is the governing body for college sports in the United States. It oversees more than 1,000 universities across three divisions, with Division I being the highest level of competition.
College basketball sits in a unique space. These aren't professional athletes on million-dollar contracts. They're university students, many of whom are 18 to 22 years old, playing for their school. That youth and inexperience is exactly what makes the tournament so volatile.
A team of seniors who've been together for four years can gel in ways that a roster of talented freshmen can't replicate, and that gap often shows up in March.
There are 31 conferences in Division I, ranging from powerhouse leagues like the Big Ten, SEC, and Big 12 to smaller conferences like the Ohio Valley and Patriot League. Each conference holds its own tournament in early March, and the winners earn automatic bids to the NCAA Tournament. The rest of the field is filled by a selection committee based on regular-season performance.
How Do Teams Qualify for March Madness?
The 68-team field is built from two types of bids.
Automatic Bids (31 Teams)
Every Division I conference holds a postseason tournament in the weeks leading up to Selection Sunday. Win your conference tournament, and you're in, regardless of your regular-season record. This is how smaller schools from mid-major conferences punch their ticket. A team could go 15-15 during the regular season, rattle off four wins in their conference tourney, and suddenly they're dancing in March Madness.
At-Large Bids (37 Teams)
The remaining spots are filled by the Selection Committee, a group of 12 conference and university administrators who evaluate every eligible team's resume. They use metrics like the NCAA's NET rankings (which factor in game results, strength of schedule, and game location) alongside the eye test. Teams on the fringe of making the tournament are referred to as being "on the bubble," and the debates around bubble teams are a massive part of the lead-up to the tournament.
Selection Sunday and the Bracket Reveal
Selection Sunday is the day the full 68-team bracket is announced live on television. It's an event in itself. Fans, players, and coaches gather to find out whether their team made the cut, and if so, where they've been placed in the bracket.
The committee doesn't just pick the teams. They also seed them from 1 to 68, reflecting how strong each team is relative to the field. The 68 teams are then divided into four regions of roughly equal strength, with seeds 1 through 16 in each region. The four No. 1 seeds are considered the best teams in the country.
In 2026, Selection Sunday falls on March 15 (March 16 AEST), with the bracket reveal at 6pm ET (10am AEST).
How the Tournament Format Works
March Madness is single elimination. Lose once and you're out. That's the entire appeal and the entire risk from a betting perspective. There's no safety net, no two-legged ties, no second chances.
The First Four
Before the main bracket begins, eight teams play four games to determine the final four spots in the 64-team field. These are typically the lowest-seeded automatic qualifiers and the last four at-large teams selected by the committee. The First Four is played in Dayton, Ohio, and it's been the traditional opening venue since 2011.
Round of 64
This is where the tournament proper begins. The 64 remaining teams play across eight host cities over two days. Matchups are determined by seeding: No. 1 plays No. 16, No. 2 plays No. 15, and so on. In theory, the higher seeds should cruise through the opening round. In practice, upsets happen every single year. The 1 vs. 16 matchup held a perfect record for the top seeds until 2018, when UMBC stunned Virginia, and Fairleigh Dickinson repeated the feat against Purdue in 2023.
Round of 32
Winners advance and the bracket narrows to 32 teams. This is often where the really tasty matchups start appearing, with strong mid-seeds colliding with the heavyweights.
Sweet 16 and Elite Eight
The Sweet 16 takes place at four regional venues, with four games at each site. Win here and you're in the Elite Eight, which determines which team from each region advances to the Final Four. These games tend to be tight, physical, and high-stakes. By this stage, the weaker teams have been eliminated and every remaining squad has genuine quality.
Final Four and Championship
The last four standing play in a national semifinal doubleheader, with the winners meeting two days later in the national championship game. In 2026, both games are at Lucas Oil Stadium in Indianapolis. The Final Four is one of the biggest events on the American sporting calendar, comparable to the Super Bowl in terms of national attention.
Do the Seeds Matter for Betting?
Seeding is the backbone of March Madness betting. Each region has seeds 1 through 16, and the bracket is designed so that higher seeds face lower seeds in the early rounds.
Historically, No. 1 seeds have won about 60% of all championships since 1979. No. 1 seeds almost always advance past the first round, though the two 16-over-1 upsets in recent years have shown that nothing is guaranteed. Seeds 2 through 4 tend to produce the bulk of Final Four teams, while seeds 5 through 12 are where the real chaos lives.
The 5 vs. 12 matchup is famous among punters. Twelve seeds have won roughly 35% of their first-round games historically, making it one of the most reliable upset spots in the bracket. Similarly, 10 and 11 seeds regularly cause problems for their higher-seeded opponents.
For betting purposes, seedings give you a starting framework, but they're not gospel. A No. 4 seed from a weak conference might be more vulnerable than a No. 7 seed from the Big Ten or SEC. Context matters more than the number next to a team's name.
Cinderella Runs: Why Upsets Happen So Often
March Madness is famous for its Cinderella stories, small schools or low seeds that go on improbable tournament runs. There are structural reasons why this happens more often in college basketball than almost any other sport.
The single-elimination format is the big one. In a seven-game NBA playoffs betting series, the better team almost always wins. In a single game on a neutral court, anything can happen. A hot shooting night, a key foul call, one player going off, these can all flip a result.
Then there's the nature of college basketball itself. Rosters turn over constantly due to graduation, transfers, and early NBA Draft betting entries. A No. 1 seed might have lost its best player to the transfer portal over the summer and replaced him with a freshman who's still finding his feet. The team might still be elite on paper, but tournament basketball rewards cohesion and experience, and those qualities don't always correlate with talent rankings.
Notable Cinderella runs in recent years include Florida Atlantic reaching the Final Four as a No. 9 seed in 2023, NC State making the Final Four as a No. 11 seed in 2024, and Loyola Chicago's iconic 2018 run as an 11 seed. For punters, these runs are a reminder that longshot bets in March Madness carry more realistic probability than the odds might suggest.
A Quick History of March Madness
The first NCAA Tournament was played in 1939, with just eight teams. Oregon beat Ohio State 46-33 to win the inaugural championship. The field expanded to 16 teams in 1951, 32 in 1975, and 64 in 1985. The current 68-team format has been in place since 2011.
The term "March Madness" was first used in connection to basketball by Illinois high school official Henry V. Porter in 1939, but it didn't become linked to the NCAA Tournament until CBS broadcaster Brent Musburger used it on air in 1982. It stuck.
UCLA holds the record with 11 national championships, including an almost absurd run of seven consecutive titles from 1967 to 1973. Kentucky (8 titles), North Carolina (6), and Duke (5) round out the most successful programs. Florida won the most recent championship in 2025, beating Houston 65-63.
March Madness FAQ
How many teams are in March Madness?
68 teams qualify for the NCAA Tournament. Four are eliminated in the First Four, leaving 64 for the main bracket.
What does 'seed' mean in March Madness?
A seed is a team's ranking within their region of the bracket, from 1 (strongest) to 16 (weakest). Seeds determine first-round matchups and the overall bracket path.
Has a 16 seed ever beaten a 1 seed?
Yes, twice. UMBC beat Virginia in 2018 and Fairleigh Dickinson beat Purdue in 2023. Before 2018, no 16 seed had ever won a first-round game against a 1 seed in the men's tournament.
How long does March Madness last?
The tournament runs approximately three weeks, from the First Four in mid-March to the national championship game in early April.
Can I bet on March Madness in Australia?
Yes. Licensed Australian sportsbooks offer markets on the NCAA Tournament, including outright winner, match betting, spreads, totals, and player props. Odds are typically displayed in decimal format for Australian punters. If you're new to how to bet on basketball, the same principles apply to college hoops.
What are the odds of a perfect bracket?
About 1 in 9.2 quintillion if you're guessing, or roughly 1 in 120 billion if you know a bit about basketball. Nobody has ever done it.
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