When a fighter is "prime" what does it mean to "you"?

[JonesJrMayweather]

A fighter's prime is that brief stretch of time where physical ability and ring knowledge intersect.

A fighter's prime is when he's experienced enough to have a complete understanding of what he's doing in the ring, but he's still at a young enough age where his raw physical skills haven't begun to deteriorate at all.

But then when that prime fighter gets into a rough fight and wins by a SD, then kayos his next opponent. Many will say he was prime in the second fight but off in the first one.