Now, didn't think this through completely, but I'm thinking it would: 1. Give incentive to the losing fighter to go for it more, especially in low finish rate divisions. The leading fighter might coast otherwise too. 2. If you're winning the last round, you're basically winning, so why not... Get a win? 3. Give more opportunities for high cardio fighters who train to get in shape. 4. Ultimate fighting was always about being as close to a real fight as possible, so if you've wasted all your energy and not been able to get ahead towards the end, then you might as well has lost anyway without rounds. (I'm a fan of the 1 round concept).