Physical or mental could be either with a good teacher. I remember at a conference getting a golf lesson on the swing analyzer. One physical detail - straighten my left leg earlier - decreased spin on the driver and improved distance by 20 yds. That was a secret to me before.
Boxing strategy has secrets. Floyds d for example nobody has figured it out so he must have secrets. At least from what I've seen people don't face him the first time and say I've seen all that before. Roger probably has training secrets he doesn't let out for Floyd. Even in an open environment like boxing
Anyway just kicking ideas around. This is a pretty good discussion.