Dallas indeed was able to sneak by the Spurs and hold their ground against Memphis and the Hornets. Lakers and Bulls the frontrunners now. Dallas and Boston the first contenders. Meanwhile Portland, first round opponent of the Mavericks, is dead last in this rating.
Also an update on the Monthly Efficiency chart. While at certain points during the season it looked like the defense would never come back to early season standards, it's now ovious that injuries in late December and early January really just threw them out of sync and they needed the remainder of the season to regroup.