At 49, Bernard Hopkins might be the last of boxing’s sweet scientists

Bernard Hopkins made a vow to his mother to not fight beyond the age of 40, and even briefly retired to keep his word.

Two months before he turns 50, Hopkins will step into an Atlantic City ring Saturday night to face arguably the sport’s most devastating puncher, Russia’s Sergey Kovalev, in a light-heavyweight title unification bout.

“She would’ve killed me herself, and I’m not kidding. I wouldn’t be on the phone with you now,” Hopkins said of his mother, Shirley, who died in 2003 at age 57. “I will always love her, but she had a left hook better than Joe Frazier.”

Hopkins recalled that he agreed to fight Oscar De La Hoya in 2004 only because it was his biggest payday. He stopped De La Hoya in the ninth round — and Hopkins kept winning, ultimately owning two light-heavyweight world titles that make him the sport’s oldest champion ever.

Now he seeks a third belt against the 31-year-old Kovalev (25-0-1, 23 knockouts) to put an exclamation point on a career built on his own redemption, after serving time in prison for an armed robbery early in his life. Hopkins says his turnaround had a lot to do with his mother’s scolding.

“She was a big influence, the one who told me, ‘If you go to jail again, I won’t come see you,’” Hopkins said.

His mother wanted Hopkins to shorten his boxing career because she’d seen the tolls of the fight game.

“She grew up in the fight area, in Philadelphia . . . my uncles fought, she knew Joe Frazier personally,” Hopkins said. “Joe wasn’t physically in the best of health before he died, Bennie Briscoe wasn’t, George Benton . . . she knew these guys, heard the speech slur.

“She knew Joe Frazier [said] of boxing, ‘You get your brain shook, your money took, and then you’re in the undertaker’s book.’ She didn’t want her baby to be punch drunk.”

Hopkins (55-6-2, 32 KOs), however, has always been a defensive, sharp-minded craftsman in the ring, able to detect an opponent’s flaws and exploit them.

Time and again, favored opponents such as Felix Trinidad, De La Hoya, Antonio Tarver, Winky Wright and Kelly Pavlik have been outsmarted and beaten by Hopkins, who follows a pure-living regimen no matter what.

An offer of cheesecake at a post-fight dinner or a celebratory bottle of wine sent by a fan to his table? Denied. “The things I don’t do, that’s my treat — the equivalent to a double slice of carrot cheesecake or ice cream,” Hopkins said.

He won’t eat red meat, shrugs off food preserved by sodium in a can or bag. No alcohol, either, and he won’t smoke.

“I avoid all the vices,” he said. “I think the average person can look at me as an example about relying on fundamental things. They play a part in my skill. Look at the longevity.”

Fighting on and maintaining a healthy lifestyle, he said, is a tribute to his mother, and father, Bernard Sr., who struggled with high blood pressure and liver problems. Both parents died before age 60.

“I learned how to eat from watching those close to me, who went to an early grave because we ate only what we could afford,” said Hopkins, one of seven siblings.

Complementing that is his boxing intellect and old-school fearlessness.

“I always wished I was in the era where we fought 15 rounds, where I had a chance to fight Sugar Ray Robinson, Marvin Hagler,” he said. “I want to push myself to bring out the best in me, and Kovalev is the most dangerous fighter in maybe any of the divisions. That’s why there’s so many raised eyebrows about this fight. That means a lot to me — everybody I’ve fought and nobody I ducked, whether I was younger or the age I am now.”

Kovalev isn’t in a sentimental mood.

“I don’t have any strategy, just to go into the ring and fight like a street fight,” Kovalev said. “My hands are my weapons.”

Kovalev is a 5-2 favorite on some betting sites.

Now that Hopkins is in the senior stage of his career, he relies more than ever on his smarts because he longer has much punching power. Since knocking out De La Hoya, Hopkins has been in 16 fights without scoring a KO. In that period Hopkins’ record is 10-4-1, with one no-decision.

So Hopkins has prepared for Kovalev by studying replays of Hagler’s 1986 middleweight title bout against John “The Beast” Mugabi, a devastating puncher Hagler broke down.

“When they say, ‘Kovalev is smashing people, he’s heavy-handed,’ what can you say after that?” Hopkins asked. “My confidence is in my intelligence. . . .

“I know I’m going to have to take some of the best punches this man has given to others who couldn’t stand up. But what happens to Kovalev when he catches me and Bernard Hopkins’ chin takes it?”

Hopkins’ ongoing popularity caused a bidding war for his services between HBO, which will televise Saturday’s bout, and Showtime, which wanted him to fight Adonis Stevenson.

“The old, sweet science of boxing . . . I know it’s not the rules today . . . the rules today are, to get on TV, you’ve got to be exciting, don’t duck punches, prove how strong you are, get hit in the face,” Hopkins said. “TV-friendly is, ‘Don’t duck.’

“But let me tell you, you have an old soul in this new world, a guy cut from the old cloth. Hit and not get hit, and I will show boxing is a sweet science.”

Follow Lance Pugmire on Twitter @latimespugmire