By Keith Idec

Floyd Mayweather Jr. wasn’t the least bit surprised Adonis Stevenson became noticeably tired during the second half of his light heavyweight fight against Badou Jack.

“I told you,” Mayweather said during the post-fight press conference following their majority draw Saturday night in Toronto.

Mayweather is one of the few fighters in the world who knows what it’s like to box at a high level after his 40th birthday. The 41-year-old retired superstar vividly remembers how much worse he felt fighting Conor McGregor last August 26 than he did when he was a significantly younger fighter.

That first-hand knowledge convinced Mayweather, whose company promotes Jack, that the 40-year-old Stevenson wouldn’t be able to keep pace with his well-conditioned, skilled challenger.

“Absolutely,” Mayweather said. “And when they fight again, the same thing’s gonna happen.”

Stevenson (29-1-1, 24 KOs) would be 41 if he and Jack actually fight again, as the Haitian southpaw’s birthday is September 22. Sweden’s Jack (22-1-3, 13 KOs) will turn 35 on October 31, but Mayweather pointed out the dramatic difference between boxing even at the advanced age of 35 and then 40.

“When you’re young – when you’re 19, you’re 20, you’re 21, you’re agile, you’re fast,” Mayweather said. “Everything you can see, you can do. Once you get up there – 38, 40, 41, it’s not the same as when you was young. You see certain things, but you’re not able to do [it] … you’re not able to do those effective things that you were able to do when you was younger. Whereas when I was 35, it was still a big difference. How old was I when I fought Canelo? I think I was 35 when I fought Canelo, so I still had it [he was 36]. But then, when I was a little bit older, I was like, I go to the gym and I’m like, ‘Yo, I still got it. But it’s not like it was when I was younger.’

“You know, when I was ‘Pretty Boy Floyd’ it was different than when I was ‘Money Mayweather.’ Whereas you see the shots come rapid, fast, different angles. But then, you know, when I got older, it was more laid back, relaxed, different. But I still had a sharp mind, so I was still able to beat fighters just mentally because I’m just years and years ahead of them. So, you know, I’m not thinking about just the first round, right then and there. I’m thinking about when we get in the fourth and the fifth round. Like I said, it’s chess moves, you know, steps ahead – 10 or 12 steps ahead.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.