I once read in a backgammon book (I think it was Robertie--I haven't read that many) that the break even point for taking a double should be 25%. If you win 25% of the doubles you accept, this person wrote, over the long run, you won't be behind any more points than if you dropped every game for single stakes (for instance, over the course of four such games, you'll be down 6-2 instead of 4-0, etc.).

This reasoning seems to me to miss one crucial factor--volatility. In a nutshell, I would rather be down 4-0 than 6-2 in, say, a 9 point match because 6-2 puts me closer to losing. Consequently, I think you need to adjust that 25% up--you need more than that to accept, and you need less than 75% to double. But I don't know how much to adjust that. I guess it would depend on the count in the match, length of the match, etc.

Thoughts on this?