Padraig Harrington beat Yeung-Sul Noh to win in Asia last season.Don’t bother arguing numbers with Padraig Harrington - the trained accountant. And under no circumstances should you play the age card and suggest that once a golfer hits the big 4-0 he’s on the slippery slope to the golfer’s graveyard.

Harrington will celebrate his 40th birthday on August 31 this year and if one of his pet theories is correct, he’s about to have one of the best years of his career.

Ignore for a moment the fact that he has spent most of his six-week winter break working on a slew of changes to his swing, his set up, his putting stroke and his equipment. He might have slipped from third to 26th in the world rankings over the past two years but at the age of 39, he believes he is a very dangerous animal indeed.

“I’ve no grey hairs at all,” he says, proudly whipping off his cap. “I’ve got the lowest hairline in the world. I have got miles to go ….”

Then he leans in with a tip that should prick up the years of golfing punters everywhere.

“Have you heard of Elliot’s Form Guide? No? It says that players win when they are 29 and 30, and 39 and 40 because they have a point to prove. A chip on the shoulder.”

Two 39-year olds have won the Masters in the past two years, Angel Cabrera and Phil Mickelson. But while just four players have won majors in their 40s since 1990, Harrington refuses to believe that the golf ball knew how old Hale Irwin, Ben Crenshaw, Mark O’Meara or Vijay Singh really were.

The PGA Tour’s obsessive chirping about the golf’s current “Youth Movement” does not register with the Dubliner, who will rub shoulders with players like 21-year old Rory McIlroy, 19-year old Korean Noh Seung-Yul or 17-year old Italian Matteo Manassero when he begins his 2011 campaign in Abu Dhabi next week.

But doesn’t he feels a pang of urgency when he sees these young guns winning on tour before they’ve even started shaving regularly? Doesn’t it make him think, it’s time to get my share of wins before these guys really take over?

“No,” Harrington says. “Because I think I am 20 years of age. That’s the issue. Because I am competing against them, I don’t see an age thing. I don’t stand on the tee and see age at all. I don’t recognise it whatsoever. I see experience, I see talent, I see all those things which may be reflected in age. But I don’t actually see the age. Age has nothing to do with it.

“It is not like soccer when they go, ‘Oh you’re 32, you’re slow.’ Or, ‘He’s 28, he’s getting slow.’ That doesn’t happen in golf thankfully. Old guys hit it a long way, young guys hit it short.

“Experience is a factor, but you see young guys with great experience who are great under pressure and you see old guys messing up. Age isn’t really anywhere near as determining a factor in golf as it is in other sports.

“This is why you have young guys who can win and old guys who can play fantastic golf. As long as you are fit and strong, and I intend to be fit and strong.”

It’s all about desire, it seems. How long Harrington can keep it up is anyone’s guess, but he appears to have no intention of slowing down.

“I certainly can’t see another six years of being really competitive but it is all to do with motivation and I started late in this game,” he says, fidgeting to get away. “I was 24 years of age when I turned pro. It is not age, it is how long you can do it before you burn out.”

Harrington doesn’t give the impression that he’s in danger of burning out any time soon. Only a player with a deep hunger for success would completely overhaul his swing in a basement room for the umpteenth time when he has three major trophies sitting on the kitchen table upstairs.

“I will be on the seniors tour and we will have this conversation again,” he says with a sigh. “You’ll say, ‘You’re 69 this year and you have changed your whole swing again. You can go back to this interview and rehash it.’”

And with that he was off home to work on his swing, pack his bags and go through it all again with the enthusiasm of rookie. He might be turning 40 this year but he’s determined to make it the roaring forties - for all the right reasons.