Question about a fighters "prime" / "past his best"

[Fenster]

you can still be on of the best in the world and be past your own best

for example in a football anology

thierry henry is not quite as quick and prolific as he once was but youd still rather have him in your team than emile heskey !!

as for mosley he was past his best when he fought cotto but pushed him close so cotto deserves credit as mosley was still a very good fighter, his performance against mayorga would suggest he has slipped further than him

in conclusion you dont have to be at YOUR best to be one of the best in the world

But then how do you determine when someone is showing THEIR very best?

Was Kostya at his best against Phillips? Was Mosley STILL at his best when first losing to Forrest? Or does the loss signal he was past it?

Have old boys like Calzaghe and Hopkins showed better form in their younger days?

I'm not sure.