Kansas City Chiefs Crowned the Decade’s Most Successful Sporting Underdogs

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Sport never fails to produce some of the most exciting storylines, whether it’s in the context of a season, a tournament, or just a single match. Underdog stories are some of the best that you can follow regardless of the sport, as they add an element of excitement and surprise when they succeed.

They’re living proof that miracles can happen, with the Boston Red Sox’s MLB World Series in 2004, and the New York Giants’ 2007 Super Bowl season in the NFL being some of the best we’ve ever seen.

But when looking at the last ten years, which sports team has defied the odds the most?

We’ve analyzed data from the last decade and identified which US sports teams have performed the best when they’ve entered a game as the underdog. Read on to discover the best-performing underdogs in the last ten years!

The Top 3 Teams by Win Percentage as an Underdog – Overall

Looking at the overall data across teams from the NFL, MLB, NBA, NCAA Basketball, and NCAA Football, we’ve picked out the best underdogs.

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Kansas City Chiefs - NFL

Topping the charts as the most successful underdog is the Kansas City Chiefs in the NFL. The Chiefs achieved an impressive win percentage of 66.67% after winning 20 of their 30 games as an underdog. As they’ve drawn once and only lost nine times, they’ve overperformed on numerous occasions, making them the most successful underdog in our rankings!

Over the last ten years, head coach Andy Reid has managed to transform the team drastically. In 2016, he finished with a 12-4 record and won the division for the first time in six years. Winning the division again in 2017, he built momentum, which set the foundation for their success with Patrick Mahomes. Mahomes helped the Chiefs to win the division for a third and fourth year running in 2018 and 2019, and they won their first Super Bowl for 50 years in 2019.

They continued to win their division every season up until 2024, including securing two more Super Bowl titles in 2022 and 2023.

Baltimore Ravens - NFL

Second on our list is the Baltimore Ravens, who end up with a win percentage of 61.9% when playing games as an underdog. In the last decade, the Ravens have played more games as an underdog than the Chiefs, winning 26, losing 13, and drawing three times. This makes their win percentage all the more impressive given the number of times they’ve overcome the favorite.

While they achieved more underdog wins over the last ten years, the Ravens haven’t quite been able to build the legacy that the Chiefs did in the same time period. The majority of this time has seen them under the guidance of John Harbaugh, who managed to deliver long-term stability and an identity to the team, often appearing in the playoffs. From 2016 through 2025, the Ravens finished either first or second in the AFC North in nine of ten seasons, with their fourth-place finish in 2021 the only exception. They won consecutive division titles in 2018 and 2019 before repeating the feat in 2023 and 2024. From 2016 through 2025, the Ravens finished either first or second in the AFC North in nine of ten seasons, with their fourth-place finish in 2021 the only exception. They won consecutive division titles in 2018 and 2019 before repeating the feat in 2023 and 2024.

Despite not reaching any Super Bowls, they’ve had standout players such as quarterback Lamar Jackson, who was drafted in 2018. Becoming a starter in the same year, Jackson established himself quickly, managing to win the NFL MVP in 2019 and in 2023. He may not have seen the same success as Mahomes, but Jackson more than transformed the way the Ravens played.

Pittsburgh Steelers - NFL

Rounding out the podium places for the most successful underdogs in US sports is the Pittsburgh Steelers, making it an all-NFL top-three. The Steelers have managed a win percentage of 60% after winning 45 times.

The last decade has proven the Steelers to be consistent throughout the regular season, but ineffective in the playoffs. Head coach Mike Tomlin has been one of the longest-serving leaders, managing to maintain a level of competitiveness regardless of any changes in the roster. Tomlin helped to coach the team up until 2025, overseeing the team winning the AFC North four times over the last 10 years (2016, 2017, 2020, 2025).

Quarterback Ben Roethlisberger was a star player for the Steelers, demonstrating his elite passing abilities regularly, with the 2018 season being a particular highlight. After he left, it was clear to see his influence was missed as the offense became inconsistent and there was an evident period of transition for the Steelers’ quarterback position.

The Top 3 Teams by Win Percentage as an Underdog – NFL

Naturally, as the overall top-three best underdogs are all NFL teams, they’ve already been discussed in the section above. This is, however, a credit to the NFL as it demonstrates just how close the league is, as even when teams are predicted to be an underdog, they can still win!

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The Top 3 Teams by Win Percentage as an Underdog - MLB

Now, let’s take a look at the best underdogs from the MLB, seeing which baseball teams are the best when they’re expected to lose:

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Houston Astros

Taking first place as the best underdog in the MLB, the Houston Astros have been the most consistent baseball team to beat the odds. With an underdog win percentage of 51.3% after 178 wins and 169 losses, they stand out as the best.

Since 2017, the Astros have enjoyed one of the most successful periods in recent MLB history. They won the World Series in 2017 and 2022 and also reached the Fall Classic in 2019 and 2021. Houston made seven consecutive ALCS appearances between 2017 and 2023 and won at least 90 regular-season games in every full-length season during that period.

Much of that success came under two World Series-winning managers: A.J. Hinch and Dusty Baker. Hinch led Houston to the 2017 championship but was dismissed in January 2020 following MLB’s investigation into the team’s sign-stealing operation. Baker, who was 70 when he took over in 2020, guided the Astros to another title in 2022. At 73, he became the oldest manager to win a World Series. Joe Espada subsequently replaced Baker ahead of the 2024 season.

Milwaukee Brewers

Then, the second-best underdog in the MLB over the last ten years is the Milwaukee Brewers, who managed an underdog win percentage of 49.5%. Considering they’ve played 364 more games as underdogs than the Houston Astros have, however, this is incredibly impressive. The Brewers won 352 games as an outsider, losing 359.

The Brewers have been one of MLB’s most consistent teams in recent years, although they are still searching for their first World Series championship. Milwaukee made seven postseason appearances between 2018 and 2025 and recorded at least 86 victories in every full-length season from 2017 through 2025. They reached the National League Championship Series in 2018 and 2025 but have not appeared in the World Series since losing to the St. Louis Cardinals in 1982.

Between 2015 and 2023, they were under the leadership of Craig Counsell – the longest-tenured manager in the franchise’s history. Following his departure after his contract expired, Pat Murphy took over and led Milwaukee to the NL Central title in both 2024 and 2025 and was named National League Manager of the Year in each season. In doing so, he became only the second NL manager to win the award in consecutive years.

St. Louis Cardinals

Finally, completing the top-three MLB underdogs is the St. Louis Cardinals, with an underdog win percentage of 47.2%. Like the Milwaukee Brewers, they’ve also played many games as underdogs, winning 345 and losing 386, making for a commendable win rate when not being the favorite.

Since 2016, the Cardinals have remained competitive for much of the period, although they have struggled to turn that into sustained postseason success. They have made four playoff appearances since 2017, reaching the postseason in 2019, 2020, 2021 and 2022. They have also won two division titles during this period, finishing top of the NL Central in 2019 and 2022.

After the departure of manager Mike Matheny in 2018, Mike Shildt took over and led the team back to the playoffs. However, when Shildt left in 2021, Oliver Marmol was appointed, winning the division in his first season in charge.

Key figures in this period include Paul Goldschmidt, who had MVP-level production and was central to the 2022 division-winning team. Nolan Arenado was also important, being an elite two-way player as he brought both offensive and defensive qualities to the team.

The Top 3 Teams by Win Percentage as an Underdog - NBA

Let’s now move on to another of the biggest sports leagues in the USA, the NBA. Being the premier basketball league in the world, the NBA always brings drama and excitement – especially in the playoffs. So, let’s take a look at the best underdogs:

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Boston Celtics

Despite being the most successful NBA team of all time, the Boston Celtics take top spot with an underdog win percentage of 43%. In the 214 games they’ve played as an underdog in the last decade, they’ve won 92 and lost 122. This gives them the best win percentage record of all NBA teams, securing first place.

Boston reached the playoffs in every season during this period. Between 2017 and 2024, the Celtics made six Eastern Conference Finals and reached the NBA Finals twice, losing in 2022 before winning their record-breaking 18th championship in 2024.

Brad Stevens coached the team from 2013 to 2021 before moving into his current role as president of basketball operations. Ime Udoka then led Boston to the 2022 Finals during his only active season as head coach, while Joe Mazzulla subsequently guided the team to the 2024 title.

Jayson Tatum and Jaylen Brown were central to this success, with Tatum developing into the team’s leading scorer and Brown winning the 2024 NBA Finals MVP award.

Miami Heat

Third place among the most successful underdogs in the NBA is the Miami Heat, who’ve become elite competitors over the last decade. In the 402 games that they’ve played as the underdog, they’ve managed to see victory in 156 games - giving them an underdog win percentage of 38.8%.

Since 2017, they’ve made seven playoff appearances, and NBA Finals appearances in 2020 and 2023. Despite not winning a championship this time, they’ve also had multiple Eastern Conference Finals runs in 2020, 2022, and 2023.

Throughout the whole decade, Miami Heat have been coached by Erik Spoelstra. He’s proven to have an elite coaching style that can adapt to different rosters and maximize underdog teams’ performance.

After joining in 2019, Jimmy Butler quickly transformed the team as he helped to lead them to the NBA Finals in 2020 and 2023. His elite performances during the playoffs earned him the nickname ‘Playoff Jimmy’ as he was known for his clutch scoring abilities and leadership.

The Top 3 Teams by Win Percentage as Underdog – NCAA Basketball

Now, let’s have a look at college basketball to see how these teams perform when they’re up against it. Below are the best underdogs in NCAA Basketball:

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Duke Blue Devils

First on this list with an underdog win percentage of 50% is the Duke Blue Devils. With 13 wins and 13 losses, they’re perfectly balanced when it comes to winning or losing in games where they’re not the favorite.

Under the leadership of Mike Krzyzewski, the Duke Blue Devils managed to have consistent deep runs and held an abundance of talent, yet couldn’t capitalize on their position to win any titles. When he departed in 2022, however, it marked the end of a dominant era. Former player and assistant, Jon Scheyer, then took over and maintained elite recruitment.

Huge stars have managed to emerge over the years, such as Jayson Tatum in 2017, Zion Williamson in 2019, and RJ Barrett in 2019 as well. Despite entering the 2019 NCAA Tournament as the overall No. 1 seed, Duke’s star-studded team lost 68–67 to Michigan State in the Elite Eight.

Arizona Wildcats

The second-best underdog college basketball team in NCAA Basketball is the Arizona Wildcats. After 50 games played as underdogs, their win percentage stands at 44%, with the Wildcats winning 22 and losing 28.

Arizona have remained one of college basketball’s strongest programs, regularly recording high win totals and competing for conference titles, although their NCAA Tournament performances have often fallen short of expectations.

Long-time head coach, Sean Miller, had them as strong contenders between 2016 and 2018, winning Pac-12 Conference titles back-to-back in the 16/17 and 17/18 seasons. However, the team saw a decline after 2019 until the end of his tenure in 2021. Tommy Lloyd then took over and had an immediate impact, winning 33 and losing four games in his first season.

Winning multiple Pac-12 titles in this period, they proved to be successful in terms of rankings, wins, and conference titles, but fell short in the latter stages of the year.

Belmont Bruins

Completing the top-three best underdog teams in college basketball is the Belmont Bruins, who achieved a win percentage of 43.5% after playing 62 games as an outside bet. Belmont won 27 and lost 35, proving they’re competitive in most games they’ve played as underdogs in the last ten years.

Rick Byrd was able to build the team into a mid-major powerhouse, winning conference titles consistently and achieving high win totals. Byrd may have departed in 2019, but his success was continued seamlessly under Casey Alexander.

The last decade has proved Belmont to be one of the best teams outside major conferences, winning Ohio Valley Conference (OVC) titles in 2016, 2017, 2019, 2020, and 2021.

The Top 3 Teams by Win Percentage as Underdog – NCAA Football

Finally, let’s review the best underdogs in college football and see which teams have the best win percentage in the last decade.

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Clemson Tigers

Topping the charts as the best underdog in college football is Clemson University, with a 57.1% win rate across the 14 games they played when they weren’t favorites.

Clemson established itself as a college football powerhouse during its peak run from 2015 through 2020. Under Dabo Swinney, the Tigers made six consecutive College Football Playoff appearances and won the national championships for the 2016 and 2018 seasons.

They’ve also had legendary players in this period too, with quarterback Deshaun Watson leading the 2016 title run and quarterback Trevor Lawrence being the face of their undefeated championship team in 2018.

Alabama Crimson Tide

Another of the most successful underdog college football teams in the last decade appears second on this list, with a winning percentage of 55.6% over nine games.

Alabama won the national championships in 2017 and 2020. Under Nick Saban, they achieved over 200 wins and six national titles until he left after the 2023 season.

The Crimson Tide remained a national contender through 2023. After Saban’s retirement, Alabama went 9–4 in 2024 before improving to 11–4 and reaching the College Football Playoff quarterfinals in the 2025 season. NFL-caliber players such as Jalen Hurts, Tua Tagovailoa and DeVonta Smith were central to Alabama’s success during this period.

Notre Dame Fighting Irish

Completing the top three college football underdogs in our analysis is Notre Dame, which won nine of its 21 games as an underdog. Its 9–12 record produced a 42.9% win rate.

Notre Dame reached the College Football Playoff in the 2018, 2020 and 2024 seasons. The Fighting Irish lost in the semifinals in 2018 and 2020 before advancing to the national championship game for the 2024 season, where they lost 34–23 to Ohio State.

The competitive nature of modern sport

So, as you can see, many teams over the last decade have proven that they can win many games despite not being favored. The data just goes to show how competitive and finely balanced modern sport has become. Regardless of who’s selected to be an underdog and who’s expected to win, it can still go either way.

It’s clear that in today’s sports, underdogs aren’t being dominated and that they’re far from helpless. Real underdog stories – the ones that truly mean something – remain a rarity, and that’s exactly what makes them so special.

Methodology

For this campaign, we analyzed data from the past ten seasons (2016–2026) to identify which US sports teams perform best when entering a game as the underdog.

Using betting odds data, we calculated each team's underdog win rate by dividing the number of games won as an underdog by the total number of games in which they were listed as an underdog.

Alongside identifying the best-performing underdogs, we also examined which teams have struggled the most when listed as underdogs and which franchises have been assigned underdog status most frequently over the last decade.

All data accurate as of 1 June 2026.