El Cid: The doubling the points lost is stuped the purpose of the points is to show if they can play not if they are good at realising when they are beet. As for a claim victory option in games like Spider Line 4 I always say good game to my oponent when I have them so they can't possibly win. If it is someone I play a lot of games I will then give them a list of every posible move I and they can make showing they have losts but I do that for those I am trying to teach only.

mctrivia: You have given me the answer!!
Let the 'doubling' affect just the Action Points.
If the player refuses the double, then the winner just collects 5 points.
If the player accepts the double and then loses, 10 points is DEDUCTED from his Action Points.
If the doubler loses, then 10 points is deducted from his Action Points total.
Perfect (the points may/will be different for pawns but the principle is the same).
Of course, some players may reckon that they will get more move points by playing on than refusing the double; perhaps the rules could NOT count any moves after a double.