Vikings: According to grenv's calculations,
Backgammon (grenv, 2007-10-04 14:05:59)
it takes 17 rolls minimum to get all your checkers home without any doubles. If you went first, your opponent would get 16 rolls. That's 33 total. The odds of not rolling doubles on any roll are 5/6, so the maximum odds of rolling a doubles free game are,

(5/6)^33 = .002438 or 1/4 of one percent, about once every 400 games.

I suspect the typical game is close to 25 or 30 moves/side, so the odds are probably around,

(5/6)^50 = .00011 or one in 10,000.
(5/6)^60 = .000018 or one in 50,000.