The Mavericks' season has been herky-jerky, full of stops and starts.

On Thursday night, it was all that, but without the stops.

The defense couldn't keep Denver's whirling, Allen Iverson-led offense from piling up points and, in the end, a victory as the Nuggets peppered the Mavericks, 122-109, in a game that was a direct descendant of the shootout days of the 1980s.

By the time the crowd at American Airlines Center dwindled in the final minutes, it was clear these Mavericks are flat-out bad right now. They have lost six out of nine, including three of the last four. Too many players are playing below expectations.

"They're not very pretty right now," president Donnie Nelson said. "But they're ours, and we love them."

That was Nelson's way of saying there will be no overreaction to the Mavericks' disjointed play through the first quarter of the season. So drop those ideas of Kobe Bryant, Jason Kidd or Shaquille O'Neal.

Instead, the Mavericks will concentrate on what it's going to take to pull out of this dreadful tailspin. They surrendered a season-high in points, forced only eight Denver turnovers, suffered 19 giveaways of their own and shot only 33.3 percent in the fourth quarter, when the game was still undecided.

Dirk Nowitzki (32 points, 12 rebounds) and Jerry Stackhouse (23 points, seven rebounds, five assists) had strong games, but anything the Mavericks did on the offensive end was wiped out with their lack of defense.

"It was a layup drill out there," Nowitzki said. "They got whatever they wanted. At no point in the game I thought we could really stop them."

Least of all when they were still in the game. A Jason Terry 3-pointer cut Denver's lead to 90-89 with 1:44 to go in the third quarter. Yes, the third quarter – a testament to the sloppy defense on both sides.

The difference was Denver's defense actually got serious the rest of the way.

Denver scored on its last four possessions of the third quarter and four of its first five in the fourth quarter to go up, 107-94. The Mavericks got no closer than nine points the rest of the way. Iverson finished with 35 points, 12 assists and six steals. Carmelo Anthony had a poor shooting night, but ended with 23 points. Linas Kleiza had 23 points off the bench for the Nuggets.

"Just got to fight through it," coach Avery Johnson said of what the Mavericks have to do. "We got to take a little time and refocus and reenergize and get back after it. The men are up for the challenge. They're disappointed. We're all disappointed. They don't want to play this way, but they'll keep fighting."

Not all of the problems were on defense. With five minutes left in the first half, Nowitzki was 7-for-9 from the field and everybody else was 7-for-24. Josh Howard fought foul problems, and Devin Harris and Terry were a combined 7-for-21 from the floor.

But nothing could overshadow the soft defense.

"Another hot player kind of burned us off the dribble, and we just got to take a little more pride in getting that guy stopped," Johnson said. "We just don't have that consistent attitude on defense. That's something we've always taken pride in. Right now, we're just trying to get one thing we can hang our hat on."

The Mavericks are 12-8. At one point last season, they were 35-8, although that wasn't such a great omen of things to come, either.

"Obviously, this is not the way we wanted to start the season," Nowitzki said. "But we're looking forward to the rest of the season. It can only get better."