What's your definition of "prime" fighter? How do you determine it?

[Chollo Vista]

By definition, prime is the following "of the best possible quality; excellent".

I consider the following when talking about a guy's prime:

Age

Value of fights won consecutively

Value of opponents beaten and who their opponents beat

Sometimes division rankings and P4P rankings are important

How far removed they are from a defeat and their condition during their defeat. If they actually loss or case of foul judges.

There's a lot to take into account when assessing a fighters prime.

What do you consider?

[Chollo Vista]

So many guys making claims about who's prime and who's not prime all the while no one can define what prime is?

[McNulty]

If you don't know, you're never going to know.

[CatchAndShoot]

If you don't know, you're never going to know.

This. You don't even have to ask this. You just know.

[Joe Beamish]

As you say, a number of factors. But it all comes down to sensing whether a guy is still able to get the most out of Experience X Athletic ability. His wisdom and smarts can make up for a certain amount of physical decline, but only so much.

Ali of the early-mid 1970s had lost a step compared to the 1960s version (though he was still faster than anyone else.) But he was a smarter, trickier fighter. Therefore still in his "prime." Until his athletic decline simply became too much.

After a certain point, you lose your ability to rebound, refuel, reload quickly. Usually by age 35 or so -- though again, it depends on many factors.

[Floyd is TBE]

When an athlete is at the absolute peak of their abilities. That's it. All that other stuff is irrelevant to me.

[John Locke]

It's a tricky subject as there are a lot of variables. I mostly use common sense, along with the things you mentioned in the OP

[mjbjst]

You can't really determine when a fighter was in his prime until he starts to decline

[Elroy The Great]

going off of a section of ones resume, the best part ?

imho, the peak of ones physicality. body fat low, testosterone high, reflexes on point. enough experience w/o damage.

being in prime condition doesnt necessarily ensure wins.

[iamboxing]

I don't consider age to be that important when considering prime. It was all downhill after Tyson fired Rooney. RJJ's athleticism declined way before the Ruiz and Tarver fights. Naseem Hamed went from Ingle's version of being elusive and hardly ever being hit to a Suarez one trick pony looking for a KO who didn't even bother with training or defense. Foreman in his 40s was a better boxer than in the 70s.