Assessing blame starts early for lottery-bound teams, and the Mavericks are no different. As you might suspect, owner Mark Cuban is ready to accept fault.

Plus, he’s ready to zero in on one of the main things he and president of basketball operations Donnie Nelson must fix in the off-season: this team’s collective basketball IQ.

That lack of savvy nearly bit the Mavericks again. They survived some boneheaded play late in regulation and prevailed in overtime, 108-105, against the Denver Nuggets on Friday at American Airlines Center.

This time, they got away with 21 turnovers, a flurry of missed free throws and some inattention to detail. The veteran trio of Dirk Nowitzki, Vince Carter and Shawn Marion did the heavy lifting, and O.J. Mayo made up for an overtime-forcing turnover with solid play in the extra period.

And so, while the playoff carrot has been snatched away from the Mavericks’ noses, that other incentive, a winning season, remains within reach. They crept to 39-40 with three games remaining and will try for the fourth time in the last three weeks to reach .500 Sunday in New Orleans.

For Cuban, the job of retooling the roster begins this summer. But he’s already got some ideas.

“Look, it didn’t work out the way we planned,” Cuban said. “It’s all on me and Donnie. It’s our job to put people in position to succeed. We didn’t do enough of it. I bust my [tail] to do as best as we can. No one hates losing more than me.”

After watching 79 games, Cuban said the lack of a point guard with moxie like Jason Kidd, or even Derek Fisher, sabotaged the Mavericks.

“I’m proud of the effort, I’m just not always proud of the basketball IQ,” Cuban said. “When you see dumb plays, sometimes they look like lack-of-effort plays when they’re just dumb. … We definitely need more basketball IQ.”

They certainly needed more at the end of regulation when Mayo committed the Mavericks’ 20th turnover of the night that allowed the Nuggets to tie the game with a Corey Brewer layup with 3.9 seconds left. Mayo then missed a finger roll at the buzzer.

Mayo then hit the Mavericks’ first five points of overtime. He finished with 20. To his credit, he didn’t get despondent after his crucial error.

“Even though we made some mistakes down the stretch, it didn’t cost us the game, just an extra five minutes,” Mayo said. “And we went out and got the win. You got to understand that there’s still more game left. You can’t dwell on turning the ball over. I didn’t try to do it, but it happened. They got the layup. But I thought we made more plays in overtime.”

Said coach Rick Carlisle: “That’s what you look for with guys. “Mistakes happen, but who can make a mistake and then bounce right back and hit two or three shots in overtime. I was happy for him because it was a rough 10 seconds there at the end.”

Carter hit a jumper with 1:52 to play in overtime for a 106-103 lead.

Both teams went belly-up on offense for a couple of possessions. Kenneth Faried scored with 29.5 to go for Denver, but Darren Collison hit two free throws with 1.9 seconds left and the Nuggets missed a final desperation heave.