Mavs on top in month of surprises

For the fourth straight week, a different Western Conference team has grabbed the top spot in our Power Rankings.

It wasn't easy to dislodge the Spurs, who continue to hold the best record, at 14-2, but the Mavericks completed an impressive week that included road victories against San Antonio and Oklahoma City, which had won five in a row entering the game. Dallas has won six consecutive games and 10 of its last 12 -- good enough to follow the Lakers, Hornets (who have cooled off after a hot start) and Spurs as West teams in the No. 1 position.

With a full month of the season in the books, there have already been a boatload of unexpected developments around the league. Instead of the usual analysis, this week's comments will focus on the biggest early-season surprise for each team.

(All stats and records are through Nov. 29.)

NBA Power Rankings