March Madness Betting Frenzy: Duke’s Odds, Underdog Hopes, and SEC’s Dominance

March Madness Betting Frenzy: Duke’s Odds, Underdog Hopes, and SEC’s Dominance

March Madness is upon us, and as always, it brings with it a whirlwind of excitement, drama, and, of course, betting. This year, the tournament is packed with intriguing storylines, from a freshman sensation to a powerhouse conference, and a two-time defending champion starting the week as a 100-1 long shot for a third consecutive title. Let’s dive into the betting landscape as the madness begins.

First up, the buzz around North Carolina‘s inclusion in the First Four has everyone talking, but the betting public seems to have its eyes set on Duke to take home the championship. Duke has attracted more bets and money than any other team at multiple sportsbooks this season. Despite superstar freshman Cooper Flagg nursing an ankle injury from the ACC tournament, the action on Duke remains strong.

Interestingly, the largest reported bet so far was placed on SEC tournament champion Florida. BetMGM reported a $100,000 wager from a Pennsylvania bettor on the Gators at 9-1 odds to win the national championship. This is just the beginning, as more big bets are expected during one of the most popular betting events in American sports.

The American Gaming Association estimates that $3.1 billion will be wagered on the men’s and women’s tournaments with U.S. sportsbooks over the next three weeks, with the majority of that being bet in the first four full days of the tournament.

Red Flagg?

Duke entered the 2024-25 regular season as +900 favorites to win it all, thanks to the presence of 2024’s top recruit, Cooper Flagg. Four months later, the Blue Devils remain atop sportsbook odds boards (+300 at ESPN BET), marking the ninth time Duke has entered the tournament as the betting favorite and the first time since 2019.

However, Flagg’s ankle injury has cast a shadow of uncertainty over the team. Head coach Jon Scheyer is hopeful that Flagg will play in Duke’s first tournament game on Friday against either American or Mount St. Mary’s. The sportsbooks are closely watching how this injury might affect Duke’s odds in the futures market.

Caesars Sportsbook’s head of college hoops, Richard Zanco, mentioned that they adjusted Duke’s odds from +325 to +375 following Flagg’s injury, briefly offering +700. Zanco estimates that Flagg, when fully healthy, is worth roughly “4.5 to 5” points to the spread.

Duke has been a popular choice in the national championship futures market all season, with a leading 21% of bets and 16% of handle at ESPN BET before the bracket reveal. Since Selection Sunday, Duke has taken a leading 40% of the money at the sportsbook, including a $28,125 wager at +320 odds, the largest on this year’s tournament at ESPN BET so far.

DraftKings sportsbook director Johnny Avello describes Duke as “a pretty good hazard” due to the team’s popularity. “There’s no love lost certainly for sportsbooks if Flagg didn’t play, but it would sure take away from the tournament too,” he told ESPN. “So, I’d like to see him be in that lineup to see if Duke can make a run at it.”

Return of the Underdog

March Madness is notorious for its unpredictability, and last year’s tournament was no exception. Forty favorites covered the spread, tied for the most in any tournament since at least 1985, according to ESPN Research. The resulting .597 cover percentage was the fourth best over that time period.

Conversely, the 27 underdogs to cover tied for the fifth fewest since 1985, with the .403 underdog cover percentage the fourth lowest over that time period. Avello regards last year as an “aberration” because the men’s NCAA tournament is an environment where underdogs generally thrive.

“Remember that we set lines on these games and the point spread is the equalizer. So if the favorites cover in the equalizing line, then it is not that we were wrong, it’s just that they had a good day or the other team had a bad day,” he said. “I think our lines at this time of the year are really solid. We’ve had a whole season of basketball and we’ve been able to adjust and make these lines, make the team’s ratings pretty strong. So it’s not about a point spread being wrong, it’s just about favorites going on some kind of a run.”

Bettors seem to be anticipating a bounce-back from the underdogs, at least in the opening round. BetMGM reports that all of its most-bet money lines by tickets are on underdogs:

• Texas +125 (vs. Xavier)

• High Point +300 (vs. Purdue)

• Drake +220 (vs. Missouri)

• Memphis +115 (vs. Colorado State)

• UC San Diego +125 (vs. Michigan)

It also lists Akron +13.5 (vs. Arizona) and High Point +8.5 (vs. Purdue) as two of its most-bet spreads.

Bet tracking app Pikkit says that its four most-bet spreads by money are also for underdogs:

• UC San Diego +2.5 (vs. Michigan)

• High Point +8.5 (vs. Purdue)

• Drake +6.5 (vs. Missouri)

• Akron +13.5 (vs. Arizona)

It Just Means More

The SEC has been a force to be reckoned with this season, with a record 14 teams making the NCAA tournament. Leading the charge is Auburn, which secured the No. 1 overall seed and is +500 to win the title at ESPN BET after starting the season at +2500. The Tigers quickly became favorites in late November and held that status for much of the season.

However, Florida has surged to become the second favorite (+380 at ESPN BET) to win the national championship behind Duke. It’s the first time the Gators are one of the top two title favorites since 2014. Florida’s long odds and popularity have made them a challenge for sportsbooks. BetMGM lists Florida as one of its largest liabilities, along with Duke and Michigan State.

Florida also holds the distinction of being tied as the largest favorite of the first round, with both Florida and Houston being 28.5-point favorites. At 26-8, the Gators are the third-best team against the spread in the field.

Notes on the SEC

• Alabama is ESPN BET’s fifth-most-backed team to win the national championship by bets and handle, attracting 6% of each.

• BetMGM took a $1,000 wager on Missouri to win the national championship at 125-1 odds.

• Shortly following the bracket reveal, Texas A&M lengthened from +5000 to +7500 to win the national championship.

Odds & Ends

Last season, men’s NCAA tournament games averaged 145.0 points per game, a five-year high. Despite the increased scoring, 55.2% of tournament games went under the total. There have been more unders than overs in each of the past five tournaments, with 56% of tournament games going under the total during that span.

Best teams in tournament field against the spread

• Robert Morris: 26-7 ATS (.788)

• UC San Diego: 25-7 ATS (.781)

• Florida: 26-8 ATS (.765)

Worst teams in tournament field against the spread

• Baylor: 12-20 ATS (.375)

• Grand Canyon: 13-19 ATS (.406)

• San Diego State: 12-17 ATS (.414)

Big Post-Bracket Odds Moves

UConn moved from 50-1 to 100-1 to win the national championship on Sunday afternoon, the largest bracket-related change in odds at ESPN BET. The two-time defending champion Huskies, who are the No. 8 seed in the West Regional, have covered the spread in a record 12 consecutive NCAA tournament games.

Other bracket-related moves at ESPN BET included:

• Clemson: from 66-1 to 100-1

• Iowa State: from 25-1 to 40-1

• Gonzaga: from 50-1 to 40-1

• Texas A&M: 50-1 to 75-1

Improving Teams

Teams that improved the most in Caesars Sportsbook oddsmaker Richard Zanco’s power ratings over the last half of the regular season:

• Michigan State: “Many have discounted the Spartans all year, but they have that stifling defense,” Zanco said, noting that Michigan State’s title odds shortened from 40-1 to 15-1 over the past 60 days.

• Kentucky: Zanco said the battle-tested Wildcats have been garnering some attention from bettors recently. Kentucky begins the week at around 40-1 to win the national championship.

• Missouri: The Tigers’ title odds have moved from 200-1 to 80-1 in recent weeks at Caesars Sportsbook. “They’ve looked impressive under [coach] Dennis Gates, but they play little defense, which could cost them down the stretch in the tournament,” Zanco said.