What Happens When You Bet Every March Madness Underdog?

Underdogs are all the rage in college basketball. Each and every season fans and bettors search high and wide for the "Cinderella" team's of March. So how profitable are those March Madness underdogs? Most importantly how can you profit by finding the betting trends in college basketball's end of season showcase?

Find out what happens when you bet March Madness underdogs with all the round-by-round data. 

What If You Bet On Every March Madness Underdog?

As you can see, blindly betting March Madness underdogs has touch and go over the past 10 years. 

Although, in recent years the dogs have been barking. Underdogs have won 33% of games (including the First Four) over the past five years, yielding  bettors over 26 units of profit. 

But, beware, last season underdogs won nearly 30% of games, and still lost bettors money. As sportsbooks hone in on large underdogs, you can bet these lines will become less and less profitable. If you want to bet an underdog, get in early before the market aids the books in adjusting their odds. 

There are bound to be upsets in the Big Dance, however, blindly betting those pesky underdogs hasn't been profitable over the last 10 years. 

March Madness Underdog Records By Round

There are many March Madness underdog betting trends to be found. Just last season, underdogs were highly profitable in the first four and first round of he tournament. Which is a March Madness trend that continues throughout as first round underdogs have be a highly fruitful wager for bettors over the last five seasons.

"F-D-U BELIEVE IT!?" 🗣️

On this day in 2023, (16) @FDUKnightsMBB shocked the nation and took down (1) Purdue in dramatic fashion 🔥#MarchMadness pic.twitter.com/MlbmEEFHhF

— NCAA March Madness (@MarchMadnessMBB) March 17, 2025

Similarly, March Madness underdogs have been a profitable play in the Sweet 16 over the past 10 years, yielding bettors nine units of profit. In fact underdogs have won 45% of contests in the Sweet 16 in the past five years, and that has risen to 52.2% in the last three years, and 62.5% just last season. 

However, while underdogs in the first round and Sweet 16 look like a surefire bet, it's important to note that the books eventually claw back their profits. Over the past 10 years, those blindly betting underdogs from the first four through to the second round are down over 50 units. 

March Madness Underdogs of +200 or Greater By Round

Here's where how to bet March Madness underdogs gets very interesting. Looking at our data, March Madness underdogs of +200 or greater have been profitable in the first round and Sweet 16 going back 10 years.

Even last season, when just three first round dogs of +200 or more won, $100 bettors lost just $45 in the first round. Those who took all the underdogs of +200 or more in the Sweet 16 gained that back with interest.

At the same time, the second round is where underdogs of +200 or more go to die. Over the last 10 seasons, those underdogs have won just 20% of contests, and lost bettors over 14 units. Some underdogs of +200 or greater I like this season are McNeese +255 vs Clemson, and Drake +220 vs Missouri.