Yahoo is nuts. Ties count as "half-wins" which i think is ludicrous. Yes, i agree with team A that they are the winner, and owe nothing to Team B. Yahoo rule exists as such, so therefore, it is the standing law. Passing a rule now wouldn't do you any good, unless it applies for next year. It falls into the ex-post facto realm, which means team A is off the hook, since there was no law in place before. Team A is your winner. But honestly, don't let a thing like this ruin your league, because it seems like you have a highly competitive league there on your hands, and that's very, very good.