Defenses are hugely important to figuring out who will win the NCAA Men's Basketball Tournament.

Since 2002, a team ranked in the top 25 of the KenPom adjusted defensive ratings has won the tournament.

These teams are the five best heading into this year's big dance. While shooting teams can go cold, it's a bit more rare for a team's defense to slump.

Here are the five teams that could frustrate opposing offenses the most in the tournament.

5. Virginia Cavaliers

The Virginia Cavaliers won the National Championship in 2019. That team had the fifth-best defensive rating in college basketball, according to KenPom.

This year's team is seventh by KenPom and fifth by Bart Torvik. In both rating systems, they are behind Rutgers, who did not make the tournament.

The Cavaliers are fifth in turnover rate on offense, which leads to fewer transition baskets against them. They were also good at defending the three-pointer, holding opponents to a 30.4% shooting percentage from behind the arc. That was good for 17th-best in the country.

Virginia is playing for a 10th seed in a First Round matchup against Colorado State. If they can win that, their strong defense could lead them to a surprising run in this tournament.

4. Auburn Tigers

The Auburn Tigers won the SEC Tournament on Sunday, and their defense was at the heart of their success. They held their opponents under 70 points in each of their three victories in the tournament.

Auburn was fourth in KenPom's adjusted defensive rating and sixth in Torvik's adjusted defensive rating.

Teams really struggled to shoot against Auburn this season. They allowed the lowest effective field goal percentage against and the lowest percentage of two-pointers made. They really limited three-pointers made, as well, ranking with the ninth-lowest three-point percentage allowed.

When you combine these defensive metrics with the fact that Auburn is also 10th in adjusted-offensive rating by KenPom, they could bust some brackets as a 4 seed in this tournament.

3. Tennessee Volunteers

Another SEC team that was strong defensively this season was the Tennessee Volunteers.

Tennessee's defense has led them to a 2 seed in the Midwest Region. Across the board, they rate highly by every rating system you can use. They are third in adjusted defensive efficiency in both KenPom and Torvik.

The Vols limit teams to a 45.4% effective field goal percentage, the sixth-lowest in the country. They also had the ninth-lowest two-point percentage against them.

Also ranked third by Sports-Reference's defensive rating, it's clear that Tennessee's defense is top three in this tournament. They rank behind the same two teams in every metric, so the hierarchy seems clear.

2. Iowa State Cyclones

The Iowa State Cyclones are nearly the consensus second-best defensive team no matter how you slice it.

Torvik has Iowa State's adjusted defensive efficiency at 86.5, well ahead of Tennessee's 91.5 in third (lower is better for defensive numbers). They also are second in numberFire's model. KenPom actually has them first, but based on all the other rating systems, we'll keep them in second.

The Cyclones excelled in forcing turnovers -- coming in with the second-highest defensive turnover rate in the nation. This is potentially more important than keeping teams to low shooting percentages, because it's easier to turn into points in the fast break.

Iowa State is a 2 seed in the tournament and will be a tough out because of the defense. The top team in these rankings learned that in the Big 12 Tournament.

1. Houston Cougars

The 30-4 Houston Cougars, the 1 seed in the South Region, are the best defensive team in the tournament.

Houston's defensive resumé is extremely impressive. They are first by Torvik, nF, Sports-Reference, and second by KenPom.

If you dig deeper, it only gets more impressive. The Cougars have the third-best defensive turnover rate and hold teams to the second-lowest effective field goal percentage. In simple points per game allowed, they allowed the fewest of any team in the entire country.

With how well they rate in so many different categories, it's no surprise that Houston is a 1 seed and the secondary favorite to cut down the nets (+600), according to the college basketball odds on FanDuel Sportsbook.

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The above author is a FanDuel employee and is not eligible to compete in public daily fantasy contests or place sports betting wagers on FanDuel. The advice provided by the author does not necessarily represent the views of FanDuel. Taking the author's advice will not guarantee a successful outcome. You should use your own judgment when participating in daily fantasy contests or placing sports wagers.