Oklahoma City Thunder star Russell Westbrook has long been criticized for his bad habits on the defensive end, gambling for steals and often finding himself out of position as a result.

However, this year, Westbrook has appeared to turn things around.

Cody Taylor of Thunder Wire notes that Westbrook is actually leading the NBA in defensive rating thus far, boasting a defensive rating of 97.8.

Now, defensive rating is a flawed statistic, as it is dependent on whom else is on the floor and also favors players with good box score stats. Westbrook racks up a lot of defensive rebounds and also leads the NBA in steals per game with 2.6.

A better way to evaluate just how well a player is playing defensively is by defensive net rating, where Westbrook is actually a net negative this season. When Westbrook is on the floor, the Thunder give up 106.6 points per 100 possessions, and when he is off the floor, they surrender just 104.8 points per 100 possessions.

Of course, we are not even halfway through the season yet, so that is a very small sample size, but Westbrook's defensive rating does not necessarily mean he has been one of the league's best defenders. The fact that James Harden was once one of the leaders in that statistic should tell you all you need to know about its overall reliability.

That being said, Oklahoma City currently boasts the third-best defensive rating in the league, so, obviously, Westbrook is doing something right, and the Thunder are doing this without their best perimeter defender in Andre Roberson. In addition to all the other numbers, Westbrook is seventh among point guards in Defensive Real Plus-Minus.

Oklahoma City is currently 22-12 and is just one loss behind the first-place Denver Nuggets in the Western Conference.