I don't think it's as simple as that, but I get what you're getting at. Angulo is another good one. It seemed a lot of throwback fighters who did 45 rounders were all slow twitch
i doubt you will find a boxer with 'slow twitch muscle fibres' because even guys like maidana are fast when your watching them close - comparatively maybe.
When I think of slow-twitch athletes I think of distance runners and inversely, sprinters for fast. Everyone has both slo-and fast-twitch muscles but like in a spectrum there's that ratio you're born with. But that's the impression I get, slo-twitch more stamina, fast twitch more explosion. And I tend to agree, most boxers in all likelihood fall towards the middle with the more "explosive" ones veering towards fast. As the OP states Margo is a good example of someone who may be on the slo-twitch side as he exhibits great stamina, chin and punch resistance. So when I think of boxers with great chins and punch-resistance, I think slo-twitch. Currently one that comes to mind is Brandon Rios; not particularly fast but can take a punch. He makes up for his lack of speed, with great stamina and endurance. ...but than you have athletic anomalies like my boy Pac who displays the stamina and punch resistance of a slo-twitch guy and the explosive ability of a fast-twitch. When you think about it, given the logic presented, it is hard to explain and I could see how PED accusations would get thrown about. But I'd prefer to think Pac is a mutant x-man that has a new evolved type of muscle tissue.:good