Last night's game and win streaks

A couple of thoughts today.  One is the game last night.  The Mavericks were at home and beat the Spurs 107-102.  They were two point underdogs and the Spurs are a good team.  

A few factors in their favor I knew about:

They had lost to the Spurs at San Antonio a few games before.

Mark Cuban had called out the team publicly and was demanding greater effort.

Effort trumps talent in the NBA.

One I didn't know about:

Joey Crawford was one of the referees. He has feuded with Duncan several times before and that would surely get in Duncans head.  It may have focused him more or less, I don't know, but he responded poorly this game.  

Selected quotes:

"I put it on my shoulders," Duncan said. "I really played an awful game on both ends. I've got to clean that up. ... They were real physical and I felt I got fouled on a couple things. But everybody feels like they get fouled sometimes. I tried to play through it, then started compounding by missing layups and missing shots. Frustrating night."

Critical phrase:  "they were real physical". that is the sign of a team that is playing hard, with sustained superior effort for the duration of the game.  Thats all one needs to know.  In fact, at the NBA level, it seems like one just needs to know who is going to play harder.  

Another thought:

I talked with my Dad last night and we talked about win streaks.  And I thought about how tough it would be to test win streaks for significance.  Essentially, if a team is winning games, are they more probable to continue winning games?  Are they on a "roll".  

And more critically, when do teams let up?  After how many games in a row will a team "ease off" or have a bad night with increasing probability?  How do I even go about testing these things?