here is an interesting stale mate breaker, offer vassel status to another player.
once a vassel offer is made, it can't be retracted (however the player getting the offer, can decide not to accept it). when making an offer, it is placed on the log, so everyone can see. and what it means is this:
player A offers to become a vassel of player B, for 20% points. If accepted, and either, player A, or player B win the game, 80% of the win points, go to player B, and 20% go to player A.
that means, if you have a 3 way stale mate (A weakest, B stronger, C strongest) once A becomes a vassel of B, he (A) can "suaside" him self on C, knowing that it once C is gone, he is sure to get the same number of points.
maybe make the offer limited to only 25%, and noone can have more than 2 vassels.