plaintiger: I just read playBunny's post about the double cube in reply to your questions on the BrainKing discussion board. The last sentence is very important,
Gammons and backgammons are not relevant when a cube offer is declined.
Keep this in mind if you are far enough ahead in the game that you have a good chance to score a gammon. If you offer a double, you opponent will decline and you'll get the one game point. If you just play on, you might score the gammon and get two game points. Playing on has one disadvantage though, your opponent might get lucky and turn the tables on you and had you doubled he would have resigned.