Czuch Chuckers: Essentially the point about dropping when losing is a good one. It isn't always easy to tell of course :)

After one move apparently 4-1 is the only way someone playing first can actually be considered to be losing (on rollouts), hence my suggestion that you refuse the double if you played 4-1 and are immediately doubled. Some might argue 2-1 as well, but that works out to about 50-50.