The Mavs could have been able to get up to the 6th seed if they defeated New Orleans on Sunday. But, as we know, they didn't. Now, it's almost impossible to end the season in 6th place. The Hornets would have to lose both of their remaining games and the Mavs has to win theirs. And, that's just not going to happen.
But, the Mavs does have a chance of falling back into the 8th spot since Utah owns the tiebreaker between the two teams. So, if the Jazz and Mavs end the season with the same record, the Mavs will be seeded 8th, and play the Los Angeles Lakers. And, I don't think any team wants to play the Lakers right now.
So, the Mavs control their destiny. If they can win more games than the Jazz, then they will remain at 7th, and avoid going against the Lakers in the first round. Who they might face as the 7th seed remains to be seen. But the Mavs need to finish the season strong to avoid a 1st round meeting with the Lakers.
