I'd be extremely shocked; stunned actually. Out of all the teams in the west, I think only the Hornets winning it all would shock me more than Dallas. Even if Dalls gets bythe Blazers ( a big IF in my opinion). There's no way they get by the Lakers or OKC.
With the addition of Perkins, Mohammed and the emergence of Ibaka, OKC is suddenly a much more physical, better rebounding, better defending team. Dallas has no one who stands a chance in hell of stopping Durant or, especially Westbrook. Five years ago, Marion could have done a respectable job on Durant, but not now. Durant is both longer and quicker than 2011's version of the Matrix. Ten years ago, Kidd might have been able to slow down Westbrook. Not now, not even close.
I don't think Dallas could beat Denver or San Antonio in a series either. They have the same problems against all the other teams in the west (except the Hornets minus David West) as they'll have against the Blazers. Poor defense and an old, slow, undersized backcourt. Dallas will be lucky to get out of the first round. And, if they do (which I don't think they will), no way in hell, short of Kobe Bryant getting run over by a bus, do they get past the Lakers in the second round second round. So, I guess talking about how they'd match up with the Spurs, Thunder or Nuggets is pretty much moot.
And, spending even one second thinking about how'd they'd match up against any of the top teams in the East is a total waste of time. So, I won't bother to go there.
BNM
