Floyd Mayweather-genetic talent or outstanding work ethic?

As in everything the right answer would be a mix. You can have the best genes for boxing (or whatever) in the world, but if you don't do anything with them you will not become a good boxer (or a boxer at all for that matter). But what is also true is that no matter how hard you try, you can't get really good at something unless you have the talent for it. What your genetic makeup is matters. Some people are born with stronger muscles and quicker reflexes than other, and even though you can certainly practice to become better, you can never practice enough to overcome what your body are capable of. Advanced math is a good example of this. Most people simply has not the brain to do advanced math, they (including me) can't comprehend it no matter how hard they try. Or think about it like flying. You can try all you want, but unless you have wings you won't be able to fly. You can only work with what you got. Sad but true.