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

[Fenster]

Older guys have always been around in Boxing, Archie Moore and Sugar Ray fought well into their 40's for example. I don't know how Hopkins does it, he is obviously in great shape all the time and i don't think he has had any serious disruptive injuries. Fighters will start to lose it from age 32 onwards on average then you have some exceptions like Hopkins and Calzaghe 37 and 43 respectively.
Jones jr, Tarver and Trinidad are shot, Mosley is very close to the end and is not the fighter he once was.
Kostya Tszyu is a perfect example of how injuries take their toll, causing inactivity and eventually age catches up with you when taking on the younger guys. He may well have been ranked number 3 by the Ring but did he deserve to be that high in 2005 after having 1 fight lasting 3 rounds in two years?
DLH looked ordinary against Forbes, has he lost it? Next week will tell us the answer.
Chavez was gone by the mid 90's, Whitaker went quickly and Tszyu who was pushing 36 when he lost to Hatton found out in one fight how quickly it comes to an end for a fighter. All 3 losing to much younger guys before calling it quits. Will DLH go one fight to many?
Mosley was not impressive against Mayorga, a guy he would have destroyed 7-8 years ago, i would hate to see him get knocked out by Margarito.
Forrest is pushing the envelope too!
I have such terrible memories of Ali continuing a career that really should have ended after the Thriller in Manilla!

You've just shown the inconsistency from fans/writers i was getting at (what the thread was about). Unless you personally held those concerns for Tszyu before the loss of course?

Kostya was the betting favourite against Hatton. P4P ranked three. And coming off destroying Mitchell.

Yet because of his loss - The impressive three round destruction of Mitchell was non beneficial to him (lack of rounds). The P4P rating was probably not deserved (probably not enough fights in previous two years). And he quickly became "old" in the fight (he lost).

Calzaghe and Hopkins are still at the very top because they have shown no marked signs of deterioration from their younger days.

Jones, Tarver, Trinidad and Mosley have. That's why it's safe to say they are "past their best" and why they're no longer P4P ranked unlike Hopkins and Calzaghe. That's the difference.

If Kostya was not P4P ranked, not the betting favourite and looked terrible beating Mitchell before fighting Hatton. Claiming he was "past his best" would be justified. But that wasn't the case.

So the argument that a still highly regarded losing fighter got "old" is all too convenient

[CGM]

Age in and of itself is not a determining factor, but age correlates to other factors that do determine performance, obviously.

As to whether or not one can say whether a fighter is actually performing at their best, surely that needs to be determined by watching them fight, and not just by a statistic. New info becomes available after a fight that wasn't there before. And I don't think it's out of line to say a fighter's peformance level, particularly endurance, can change from one fight to the next, or over a period of limited activity. As to the exact reason for that change, I suppose that's open to debate.