OK tell me where I'm wrong here (seriously). Maybe I don't know what I'm talking about.
Start the other 7 footer (Nazr/Rasho, your choice). Have Duncan guard Howard. He hasn't been as offensively killing as other Mavs. And when Duncan guards Dirk, so be it. Tim is a how many time All-Star, 3 time Finals MVP, All-Defense, etc. At some point he has to be a big boy too. We can't be protecting him all the time. He is a top player in the league and should be able to defend Dirk at least some of the time.
And besides what good has been keeping him from guarding Dirk done? He still has 4-6 fouls at the end of every game anyway.
It was fine to experiment with small ball to see if it would work (Phoenix last year) and if it did, fine stick with it. Nothing wrong with trying. It's obvious it's not working this series. Some one else in this thread mentioned Nazr's/Rasho's stats in two wins over Mavs this season.
IT'S TIME TO PLAY SPURS BALL!!!