Merchant concluded: "Yes, there are freaks. Hopkins. But that's not normal. Younger, quicker guys trying to prove something to the world usually beat the older guy."
Mancini said his final fight, at 31, revealed the inner conflict of a maturing man and a youthful ego. He signed to fight former world lightweight champion Greg Haugen.
"It's not all about money. It's wanting to know — and believing — that you can still get up for a world-class event," Mancini recalled.
In January 1992, Mancini started training camp without his family and infant son. Each afternoon he'd listen to Eric Clapton's "Tears in Heaven."
"I'd think of being away from my wife and son and bawl like a baby," Mancini said. "I was destroyed before I ever got in the ring. I told my assistant trainer 10 minutes before the fight in the dressing room, 'I got no business being here.'"
Mancini suffered a final defeat by technical knockout in the seventh round.
Veteran matchmaker Bruce Trampler has watched thousands of fights and knows the telltale signs of an aging boxer.
"If a guy can't defend a jab, that suggests his decline has begun," Trampler said. "The younger, fresher fighter doesn't wait for the message of an opening to punch to reach his brain. He just does it. You can actually see the older fighter waiting on the message before he punches.
"And the worse a fighter declines, the more he's at risk. We can start and finish that story with Muhammad Ali."
Trampler reminded that few ever foresaw that the brilliant Cassius Clay, who beautifully slipped punches by turning his head at the last instant, would transform into the sad Ali at the end of his career.
Trampler recalled his mentor, former Madison Square Garden matchmaker Teddy Brenner, saying in 1978 that he was going to bet some money on young Olympian Leon Spinks to upset Ali after watching the champ get hit hard in his prior fight against Earnie Shavers.
"You have no idea how bad Spinks is," Trampler told Brenner.
"You have no idea how bad Ali is," Brenner corrected before Spinks shocked the world.
One of the best bouts of all time was "The Thrilla in Manila" in 1975 when Ali was 33 and Joe Frazier was 31.
"Ali didn't have the legs to elude Frazier, so he got hit and had to fight," Merchant said. "What a fight it was."
Man versus age usually is.