Does Betting Every Underdog in March Madness Work? A 2025 Experiment

Rule 1: Game Selection

I will be betting on all games, including the First Four, as long as the moneyline for one of the teams is higher than +100. If the odds for both sides are lower than that, which happened a few times last year, I will exclude the game.

I thought about adding more criteria, like only gambling on at least 5-point underdogs and such, but I decided against it. I want to keep it simple and simply bet on every team that’s expected to lose.

Rule 2: Market of Choice: Moneyline

I tried both moneylines and spreads last year but wasn’t happy with the latter. That’s why I’m sticking with moneyline wagers on March Madness underdogs in 2025. Nice and simple!

Rule 3: Line Shopping

Using a single sportsbook for underdog betting would be very limiting, so I will use multiple March Madness betting sites. At the same time, I want to keep it fairly simple and easy to replicate for a regular college basketball fan.

That’s why I decided to limit the number to three bookmakers: Bovada, BetUS, and BetOnline. They are my favorite US sportsbooks and consistently deliver high odds, as well as cool March Madness bonuses and promos.

I won’t use any offers, though, I want to see how this works without any extra help. I will simply check the bookies and get the best March Madness odds and lines for the purpose of my approach.

Rule 4: Stakes

I only bet $10 per game last year because I targeted both spreads and moneylines, but I’m raising the stakes to $100 per wager in 2025! With the March Madness underdog betting spreads out of the way, the risk will be more manageable, so I’m happy to give it a proper go!

Rule 5: Results and Tracking

I will track my March Madness underdog betting results by posting every single bet in this article before the games (odds and lines included) and updating the outcome when the game is finished. I will provide updates after each round of the competition, showing my results and providing commentary on how the whole test is going in this March Madness bracket betting.

Update 1 (March 17)

Here we go! We didn’t include the First Four last year, but we decided to do it in 2025. I’ve added all underdog picks for this stage. I didn’t add picks for round 1 since BetUS is yet to publish the moneyline odds. As soon as they are up, first round bets will be added, too. You can follow the results in the table below.

Update 2 (March 18)

I’ve added all first round games so far, with the exception of the ones still waiting for the First Four to finish. I will add these to the table below, as soon as the moneyline odds are up. I have high hopes for the opening round because our study on March Madness upsets by round shows round 1 delivers the most surprising scores.

Update 3 (March 20)

The First Four brought only one win, but it’s early days, so I’m not worried. Today is the first round, so I have high expectations for some juicy wins. I’ve added the odds for all matches from this round, with the exception of the game between Mt. St. Mary’s and Duke, because the moneyline odds are not available. As soon as they show up, I will ad that one, too.

Update 4 (March 21)

The first round started well with some good upsets, most notably McNee State beating Clemson on the juice price of +282, but the end result was far from ideal. We had a total of 4 upsets from 16 games, losing some money in the process. The balance currently stands at almost -$900, so let’s hope the second day (and second round) are better.

Update 5 (March 22)

The 2025 tournament has been brutal for underdog betting so far. We not only have very few surprises, there are no big ones whatsoever. As a result, the experiment is down $2k after the first round. On the bright side, there are many games left, so there’s still time to turn it around!

Update 6 (March 24)

The first two rounds have been brutal for underdogs, with very few surprising results and lack of big wins. We were on the brink of a couple of huge upsets in the second round, but UConn and Colorado State lost by a combined three point as huge underdogs. Let’s hope upsets pick up from the Sweet 16 on! I will add the games from this stage on Tuesday since not all bookies have lines for all games as of Monday. In the meantime, feel free to check our Sweet 16 predictions.

Update 7 (March 26)

I’ve added the Sweet 16 bets, and I have a good feeling about this round. Multiple underdogs are more than capable of delivering an upset, so let’s hope this is the turning point this year.

Update 8 (March 29)

My last update aged very poorly, after the Sweet 16 didn’t produce a single upset! Honestly, this might be the worst year for backing March Madness underdogs in the history of the tournament.

The experiment will certainly result in a significant loss and serve as a reminder of the ugly side of sports betting. That’s why bankroll management is important and you should always place wagers you can afford to lose.

With that in mind, we still have some games left and I’ve just added the Elite 8 bets. Let’s hope for better luck in this stage, as we saw multiple razor-close games go the favorite’s way so far.

Update 9 (March 31)

When all top seeds reach the March Madness Final Four, you know it’s not the best year for backing underdogs! The results have been brutal so far, with only three games left, but I will still keep going and add the last few bets on Tuesday.

Moneyline Betting Summary

Summary

• • Total bets: 63
  • Bets won: 20
  • Bets lost: 43
  • Total staked: $630
  • Total Returned: $640.55
  • Balance: +$10.55

UPDATE After The First Four: So far, so good for my moneyline bets! We already have two early winners, netting a nice profit for the opening stage of the tournament. It’s way too early for any conclusions, but I’m happy with the start.

UPDATE After Thursday, March 21: I’m starting to regret betting only $10 per underdog so far! We had a few huge upsets this Thursday, with Oakland leading the way with a +700 victory against Kentucky. This one busted my bracket, but brought me a big win for this experiment. Overall, I’m over $60 ahead so far from moneylines, which is much better than I expected. I’m excited to see what happens next!

UPDATE After Round 1: The results so far are nothing short of amazing! After Oakland gave us a massive win on Thursday, Yale did the same on Friday. The Bulldogs beat a high-flying Auburn for a +615 win, on top of several smaller underdog wins.

We’re over $50 ahead on Friday alone, and well over $100 in the green overall up to this point. I now officially regret picking $10 instead of $100 as the bet size, but I won’t make the same mistake next year! I’ve added all bets for the second round, the odds for the last two are not available, but I will add them soon.

One thing I’ve noticed when I was placing my second-round bets is that BetOnline had the best odds, often exclusive but sometimes tied, for 13 out of the 16 moneyline wagers. If you’re going for only one bookmaker when betting on March Madness underdogs, you should use this one.

UPDATE After Saturday, March 23: yesterday was a reality check that was probably overdue. After a historic first round for the underdogs, all eight favorites won their second-round games on Saturday! As a result, we’re now “only” $38.05 ahead from the moneyline bets, which represents almost a 10% pure profit after $400 placed so far.

UPDATE After Sunday March 24: the second round continued to be brutal, so the moneylines are officially losing money now! We’re $15 or so behind, but there’s still time to turn it around. I’ve added the bets for the Sweet 16 (for the spreads, too). If you plan on targeting this round, you should check my Sweet 16 best bets. My picks for the first round did really well, and I expect more of the same!

UPDATE After Thursday March 28: The Sweet 16 started with a bang! We had three moneyline winners in four games last night, putting us back in the green. Another day like that on Friday would guarantee a profit from this experiment, but let’s be patient for now.

UPDATE After Friday March 29: Friday was another good day for the moneyline bets, with two decent wins. The overall profit stands at $47.55 with only 7 games to go in the tournament, so it’s going well. I’ve added the Elite 8 bets in the table below, in case you want to check the odds before the start of the next round.

UPDATE After Sunday, March 31: The Elite 8 started really bad for our experiment, with all three underdogs losing in the first three games. Fortunately, NC State won the last game to keep me $40 bucks ahead with three games left to play. This part of the experiment will end on a profit no matter what! I’ve added the Final 4 bets here, so I’m ready for the next stage!

UPDATE After FINAL 4: The Final 4 brought no upset wins, so we’re just above $20 ahead so far. Let’s see if Purdue can add to that tally in the championship game.

Note: The following games were excluded because the moneylines for both sides were shorter than or equal to +100. You won’t find them in the next section for the same reason.

• • Michigan State vs. Mississippi State (Round 1)
  • Nevada vs. Dayton (Round 1)
  • Texas A&M vs. Nebraska (Round 1)
  • Colorado vs. Florida (Round 1)

Spread Betting Summary

Summary

• • Total bets placed: 63
  • Bets won: 26
  • Bets lost: 37
  • Total staked: $620
  • Total Returned: $497.97
  • Balance: -$133.13

UPDATE After the First Four: the spreads are currently struggling a bit since we only have two winners. Both underdogs that lost did so with a wide margin, but it’s not the end of the world. Let’s see how the rest of the tournament goes!

UPDATE After Thursday, March 21: We’re hitting a respectable 50% of our wagers, which is enough for a small loss of $8.61. Coincidentally or not, that’s almost exactly equal to the 5% margin most bookies are applying to spreads. It’s almost as if they know what they are doing, lol!

UPDATE After Round 1: I predicted that spreads would be losing slightly because the bookies are very good at picking the right lines. It’s almost scary how accurate they are, with the 32 wagers placed split right down in the middle with 16 wins and 16 losses. The result is a slight overall loss that’s roughly equal to the margin. Let’s see if this improves going forward, but I don’t have high hopes for this part of the experiment.

UPDATE After Saturday, March 23: This is the first day in which the spreads outperformed the moneylines, because two of the underdogs stayed within the line. Still, it was a losing day overall and this part of the experiment isn’t going well. It’s almost guaranteed to lose money at this point, so I’m once again happy that I went for $10 wagers! There’s still time, though, so let’s see what happens.

UPDATE After Sunday, March 24: The second day of the second round didn’t go well for the spreads. The results continue to sink, and I’m almost $100 bucks behind now! This one is going to end in the red, no matter what, until the end of the tournament.

UPDATE After Thursday, March 28: We won three of the four spreads yesterday, getting some money back. Even after that, the balance is close to -$80, and we have 8 games left, so even if all of them are wins, this part of the experiment will lose me money. I can’t say I’m surprised, but let’s wait and see what the final results will look like.

UPDATE After Friday March 29: The spreads got another slightly losing day after two wins and two losses on Friday. All Elite 8 wagers are placed, so I hope to at least get some of my money back before the end of the tournament.

UPDATE After Sunday 31: The spreads have let me down big time, as I’m around $100 bucks down after the Elite 8. I’m glad that I didn’t pick $100 as the default wager, though, so that’s a relief! Let’s see what happens in the last few games.

UPDATE After The Final 4: The spreads have been a complete disaster and will lose me over $100. On the bright side, this could’ve been over $1k if I went for $100 wagers!