Not a very serious run, seeing how it would rely so heavily on RNG, but here are the rules: -Run start when you start Mac's last stand -You are not allowed to lose up until you have beaten Mr. Sandman once -After you have beaten Mr. Sandman for the first time in Mac's last stand, you can only lose to Mr. Sandman (losing as fast as possible, of course) -You then have to get your belt back from Mr. Sandman -You can only lose your belt to Mr. Sandman -the run end when you lose your belt to Mr. Sandman for the 3rd time and the credits rolls

To make it short, the run start when you start Mac's last stand, you have to beat Mr. Sandman 3 times and lose to Mr. Sandman 3 times. Therefore you have to win all the other fights in Mac's last stand.