The 2020-21 NBA season has got off to a blistering start, with quite a few surprises and some big names registering monster performances. Apart from good offensive displays, the 2020-21season has seen some surprisingly effective defensive performances from teams that were expected to roll over easily.Through 13 games the Lakers are 10-3 for the league’s best record.7-0 on the road- only team undefeated and set a new Lakers Franchise record for best road startAnd LeBron James at 36 in year 18 is the best Offensive and Defensive player in the NBA...Undisputed GOAT pic.twitter.com/CcKL9POPCT— LeGOAT James (@LBJgoat_talk) January 15, 2021With the usual suspects such as the LA Lakers and the Philadelphia 76ers starting the season in good defensive shape, teams such as the Dallas Mavericks and Utah Jazz have also looked good on defense so far.In this article, we look at the 5 best defensive teams in the 2020-21 NBA season so far.NBA 2020-21: The five best defensive teams thus far#1 LA LakersThe LA Lakers seem to have improved an already impressive defensive unit with the additions of Marc Gasol, Dennis Schroder, and Wesley Matthews. This is in addition to the stifling rim protection provided by Anthony Davis and the defensive versatility that LeBron James possesses.The Purple and Gold now lead the NBA in defensive rating 🛡🛡🛡 pic.twitter.com/LoZ9qEnJNv— Los Angeles Lakers (@Lakers) January 14, 2021The LA Lakers are currently averaging 38.1 defensive rebounds and a defensive rebound percentage of 76.1, which are the second-highest averages across the league.#2 Cleveland CavaliersThe Cleveland Cavaliers might not have had the best of starts to the 2020-21 NBA season but they have looked brilliant defensively. Andre Drummond currently leads the rebounds category for the 2020-21 NBA season, although the Cleveland Cavaliers need to improve on offense as the season progresses.The Cleveland Cavaliers have looked like an elite defensive teamHead coach J.B Bickerstaff has overseen a cultural change defensively and Cavaliers fans will be impressed with their showing at that end of the court. Of course, considering the injuries they are dealing with, the Cleveland Cavaliers have certainly exceeded expectations so far.#3 Dallas MavericksAnother surprise addition to this list are the Dallas Mavericks, who have registered a defensive rating of 105.5. This is a huge improvement on the 112.5 rating they had last time around. The Dallas Mavericks had a tidy offseason and have added some much-needed rim protection to their team.The Mavs are officially an elite defensive team. They are 2nd in the NBA in DRTG (104.6), and nearly tied for 1st with the Lakers (104.4). @luka7doncic, has contributed to it, showing great improvement on that end. Last night, he had a career-high 4 blocks along with 2 steals: pic.twitter.com/a8nJURLFE1— Mavs Film Room 🐴 📽 (@MavsFilmRoom) January 14, 2021Moreover, the Dallas Mavericks have also dealt with multiple injuries to starters and were missing Kristaps Porzingis’ offensive presence as well.As the season progresses, the Dallas Mavericks may further improve, which is required if they are to go on a deeper run in the playoffs. They currently have a 6-5 record.#4 Philadelphia 76ersThe Philadelphia 76ers have, for the time being, improved their defensive rating from around 110 to 106. The duo of Ben Simmons and Joel Embiid has managed to stay fit in the 2020-21 NBA season so far. The addition of Dwight Howard, as well as the versatility of Tobias Harris, has resulted in one of the strongest defenses in the NBA.Joel Embiid and Nikola Jokic are both top 5 MVP candidates so far this season: Jokic: 24 ppg, 12 rpg, and 14 apg on 62% shootingEmbiid: 28.3 ppg, 13.3 rpg, while also being one of the best defensive players in the leagueFolks have said great center play was dead.....#NBA pic.twitter.com/wo8kgeyXIb— Scott 🦅🤟🏾 (@ScottyDrowned) January 7, 2021The Philadelphia 76ers began the season with a defensive rating of 99.6 during their 6-1 start. However, they have eased off since as the team are missing several players. The Sixers are among the favorites to emerge from the East and much of that is down to their improved defensive showing.#5 Milwaukee BucksAlthough the Milwaukee Bucks have not shown the elite level of defending they did throughout the 2019-20 regular season, they have three elite defenders and are bound to improve as the season progresses.Holiday and Giannis in action for the Milwaukee BucksThe recent addition of Jrue Holiday, along with the duo of Giannis Antetokounmpo and Khris Middleton makes for a lockdown defensive unit. It is only a matter of time before the Milwaukee Bucks improve on their defensive rating of 107.4 in the NBA 2020-21 season.