Less than a week ago, I wrote about how the Timberwolves' defense was improving. Sorry.

It was true at the time, and it was the driving force behind a 13-11 stretch. The danger of isolating numbers such as that and declaring you've found a trend, of course, is that you are just as likely to watch things regress to the mean.

Exhibits A, B, C and D: the past four Timberwolves games, when their defense has been truly awful — bad enough to incur the public wrath of coach Tom Thibodeau, who for all his sideline barking this season has tended to protect his players with his comments.

Not Monday after a 115-113 loss to the Heat. "This isn't football, where there's an offense and a defense. You have to play both sides of the ball to play it well," he said, among other things.

He's right. The Wolves are 0-20 this season in their 20 worst defensive performances of the year — including the past four games.

Read Michael Rand's blog at startribune.com/randball. michael.rand@startribune.com.