The underdog is one of the most well-known sporting terms around. Simply put, it's the player or team that's the least likely to win their bouts. They're the ones that have the smaller odds to win, they're the worse team on paper, and they rarely pull it off. In this post, we'll be doing exactly that by looking at the greatest underdog runs in NBA Playoffs history.

When they do pull it off, however, it can produce some of the greatest moments in sports history. The unexpectedly tight matchup and the eventual upset to defy the odds make for the most heartwarming stories. These are the teams that tend to capture the hearts and minds of every fan of their respective sports.

In this piece, we take a look and rank the 5 greatest underdog postseason runs of this century. These teams went into the NBA Playoffs with little-to-no expectations of progressing past the 1st or 2nd round, but have managed to shock the world by reaching unprecedented heights.

We'll be ranking the teams based on their NBA Playoff runs in relation to their regular season standings and expectations. In essence, the more a team exceeded their expectations, the higher their placement will be on this list.

With that, let's get into the teams that shocked the world.

2006-07 Golden State Warriors

Dubbed the “We Believe” Warriors, 2006-07's Golden State team is the first entry of the list.

Already in a 13-year hiatus from the NBA Playoffs, the Golden State Warriors weren't looking their best to break the streak. They had just come off a 34-win season, good for just 13th in the Western Conference and dead last in the Pacific Division. The team didn't start the season in great form, only winning 19 of their first 40 games.

However, the team underwent a ridiculous 8-player trade in the midseason in the bid to shake things up: the Warriors notably got key pieces Al Harrington and Stephen Jackson (who went on to become GSW's 2nd and 3rd top scorers respectively) in the transaction.

After the huge roster change, the team posted an improved to 23-19 record, including a 5-game winning streak to end the season to clinch the 8th seed.

They then had to go against the league MVP Dirk Nowitzki and his Dallas Mavericks, who just came off an NBA Finals run. Don Nelson's “We Believe” Warriors had 14 to 1 odds to the Mavs' 4 to 1 to win the series.

Not only did the 8th seed Warriors beat the 1 seed Mavs, but they also managed this improbable feat in just 6 games. The trio of Baron Davis, Jason Richardson, and Stephen Jackson, flanked with quality role players Matt Barnes, Andris Biedriņš, and others managed to produce arguably the biggest upset in modern NBA history.

They did lose in the second round against the Utah Jazz in 5 games, hence their placement on the ranking.

2010-11 Memphis Grizzlies

The most successful era of Memphis basketball to date, the Grit and Grind Grizzlies exhibited all the traits of an underdog worth rooting for.

With stars Mike Conley and Marc Gasol being flanked by the likes of Zach Randolph, Tony Allen, and Rudy Gay, all of whom represented Memphis basketball to the tee. In a league with a hyper-focus on high-flying offense, the Grizzlies were a throwback to the likes of the 2003-04 Detroit Pistons (but more on that later). They had unrivaled hustle on defense and a dominant inside presence with Gasol and Randolph. The team finished with a 46-36 record in the 2020-11 season, good for just the 8th seed.

They then had to face the 1 seed, the powerhouse San Antonio Spurs who would go on to appear in two straight NBA Finals just a season later. It looks like a severe matchup for the Grizzlies on paper, but the two teams actually split their regular season matchup evenly. Nevertheless, the Grizzlies only had 17 to 5 odds to win the series, while the Spurs had 4 to 17.

Zach Randolph destroyed the old-looking Spurs on the inside, averaging 21.5 points and 9.2 rebounds for the series. He led both teams in scoring three times, including a massive 31-point, 11-rebound outing in Game 6 to clinch the series.

The Grizzlies would do better than the “We Believe” Warriors in the second round; they managed to push the exciting Oklahoma City Thunder to 7 games before getting eliminated.

2019-20 Miami Heat

The most recent NBA Playoffs underdog of the list, the Miami Heat made waves in the Orlando Bubble last year as they made an unlikely run to the NBA Finals.

The Miami Heat were seen as a potential 8th-9th seed in the 2019-20 season, even after the acquisition of All-Star Jimmy Butler in the offseason. Nobody expected Coach Erik Spoelstra's team to do much in the much-improved Eastern Conference, but they ended up with an unlikely 5th seed finish. The Heat looked impressive all season long, with All-Stars Jimmy Butler and Bam Adebayo flanked by sharpshooters Tyler Herro, Duncan Robinson, and veterans Jae Crowder and Andre Iguodala.

After an emphatic sweep of the Indiana Pacers in the first round, they met Giannis Antetokounmpo's Milwaukee Bucks in the ECSF. The Bucks were just behind the Los Angeles Clippers and Los Angeles Lakers as Championship favorites and had 2 to 9 odds of defeating Miami. The Heat, meanwhile, only had an 18 to 9 odds of making it past the 2nd round.

Miami absolutely totaled the Milwaukee Bucks in just 5 games, limiting the 2x MVP to just 21.8 PPG on just 41.7% shooting with their patented wall defense. Butler averaged 25, 5, and 4 on more than 53% shooting from the field.

The Heat then took it to another level, beating the higher-seeded Boston Celtics to earn set-up a Finals match-up with LeBron James' Los Angeles Lakers. They would get felled 4-2, but the plucky Heat team certainly shook the Lakers as the only team to take them to 6 games that postseason.

2003-04 Detroit Pistons

Before Grit and Grind, there was the '04 Detroit Pistons, who went all the way to the promised land against all odds.

Almost every single fan tipped the powerhouse Los Angeles Lakers to win the chip that season, with a prime Shaquille O'Neal and Kobe Bryant being joined by veterans Gary Payton and Karl Malone in their twilight years. Additionally, Kevin Garnett's Minnesota Timberwolves were in prime position to win their very first Championship as the 1 seed in the tough Western Conference. It was a lackluster Eastern Conference, however, that allowed the Detroit Pistons to reach the NBA Finals; only Jermaine O'Neal's Indiana Pacers posed any real threat to the Pistons.

The Chauncey Billups-led Detroit, flanked by Rip Hamilton, Tayshaun Prince, Ben Wallace, and other quality pieces, were a good unit themselves. However, no one expected them to match up well against the LA Lakers, who were fresh off a three-peat and a Finals loss the previous season. Indeed, the Pistons were the underdogs, going in with 15 to 1 odds to win the Championship; the Lakers, meanwhile, had 7 to 5 odds to win their 4th ring in 5 years.

Detroit's physicality, defense, and overall team chemistry would kill the old-looking Los Angeles Lakers, despite the latter sporting four would-be Hall-of-Famers. Not only did the Pistons defeat the Lakers, but they also did so in brutal, convincing fashion; Billups and company ended Shaq and Kobe's run in just 5 games.

2010-11 Dallas Mavericks

Dallas' first and only Championship to date is perhaps the most beloved NBA Champions of all time.

Dirk Nowitzki's Dallas Mavericks were far from favorites in the 2010-11 season. Kobe Bryant's Los Angeles Lakers were looking to claim their second three-peat, the Grit and Grind Memphis Grizzlies were on the rise, the Chicago Bulls were looking to make a statement with MVP Derrick Rose, and of course, the much-maligned Miami Heat Big 3 has just been formed.

Nobody expected Nowitzki and a bunch of role players to make a run to the NBA Finals. However, with the likes of Jason Terry, Peja Stojaković, and Shawn Marion (among others) stepping up massively in the postseason, the 3-seed Mavericks managed to shoot their way to the NBA Finals. On the way, they swept the Lakers and beat the up-and-coming Oklahoma City Thunder to set up a rematch of the 2006 Finals with the Miami Heat.

LeBron James, Dwyane Wade, and Chris Bosh looked to take the Heat's second-ever Championship at the expense of the underdog Mavericks. Dallas went into the Finals with an 8 to 5 odds to win it all, as opposed to the Heat's 1 to 2.

With an absolutely inspired performance from the talismanic Dirk Nowitzki, as well as some hot shooting from Jason Terry and company, Dallas absolutely ran the Heat out in just 6 games. Despite Dwyane Wade's monstrous scoring efforts, Dallas' team basketball embarrassed LeBron James and company, with the previous season's MVP averaging only 17.8 PPG for the series.

Dirk and the Mavericks' Cinderella NBA Playoffs run culminating with a win against the biggest villains of the NBA at the time makes this the greatest underdog NBA Playoffs campaign in NBA history.