Foreman's prime was just 3 fights...a "shopworn" Joe Frazier...Joe "King" Roman...and Kenny Norton...January 1973 to March 1974...
His utter peak is probably around 72 up to and including Ali. He would have beaten most of the greats that night. Tho his form dropped off he would have still been "prime" when god came and visited him.
Strange how people imagine his prime suddenly started the night he beat Frazier. Watching Foreman progress I would say around early 1972, he is looking better than most of the previous year & as strong as he would by January of ’73. His prime did end abruptly however. He was never the same after Zaire.
Late 70s when he wasn't boxing. Fighters are typically in their absolute prime right before they hit 30. Mentally its a whole different discussion.
Many champs, not all peak right before they win it all then many drop after. They’ve reached the pinnacle they have the money and fame.Theh accomplished the ultimate goal already, They don’t want to waste time in a gym all day. Baer, Liston, Tyson, Ingo, Ruiz, Bowe, and many others including Foreman declined quickly after winning it all. Done Foreman id say the same as everyone else here 72 seems about right