ZERO PERCENT!? That's asinine... For everything Floyd lacks in grappling, jiu jitsu etc, he's still the definition of Elite in one discipline of MMA... boxing / striking. There's even precedent of a Boxer KO'ing a UFC champion rather embarrassingly... Tim Sylvia vs 50 year old Ray Mercer. Even in the Couture vs Toney fight... Couture was so scared of Toney's hands... he took the lowest single leg dive I've ever seen and then worked toward a submission. But that's still man vs man. Floyd is a top athlete. He would be the taller, heavier, faster, stronger fighter. He would be in 4 oz gloves, and the fight starts standing. Rousey may be an excellent judoka / arm bar practicioner but she is not an amazing wrestler... She has not shown an ability to shoot singles or nail power doubles and Floyd would only have to utilize his excellent movement and that sublime jab to prevent her from closing distance into the clinch. If Rousey were to get a take down and gain dominant position, ok, fine... she probably could win, but literally every moment before that happens, she's at a MASSIVE disadvantage. And there are many examples of strikers lasting long enough to blast submission speciaists long before they ever get a chance to take it to the ground. If Rousey took anything close to the approach she did against Corriea... she's knocked unconcious inside the first minute. While I'd give Rousey a chance to win if she secured a takedown... I'd favor Floyd more times than not... and if Floyd is given a couple months to train basic takedown defense, it's not even close.