Bagman with a biro

Charlie Mulqueen speaks with Colin Byrne, caddie to Retief Goosen.

Even so, Colin Byrne, caddie to Retief Goosen as the South African defied the pressure to capture his second US Open title, is still bemused at how few butterflies were swirling in his stomach as he and his boss came down the final stretch.

Byrne says the New York fans were very hostile. They shouted things like "go and three putt and make it exciting" or "it's yours to lose". Anything that might put Goosen off and open the door for their favourite, Phil Mickelson. Colin claims he and his player heard this and more but were able to turn it to their advantage.

"You can either ignore all that stuff or make it work in your favour," he says.

"Retief fed off it and I took my mood from him. A caddie can get caught up in the emotion and start making mistakes. I'm still surprised by this but I wasn't especially nervous because, I suppose, I was so focused. That also came from Retief. It might have been different with any other player but he just exudes confidence. The more they shouted, the quieter and more resolute he became. We had prepared very well for Shinnecock. The homework was done and we were on the same wavelength."

How they combined to thwart the jingoistic crowds, Mickelson and Ernie Els is part of golfing folklore. The victory was followed a fortnight later by a smashing, almost runaway win in the Smurfit European Open at The K-Club. Last week, the South African shot 64 on the final day of the Tour Championship at East Lake in Atlanta to round off a wonderful campaign. It has all served to propel Colin Byrne into the domain of the 'super-caddie', populated for so long by people like Peter Coleman and Dave Musgrove and nowadays by Steve Williams (Tiger Woods), Rikki Roberts (Ernie Els) and one or two others.

Goosen's victories at Shinnecock and East Lake earned him around $2m. The going rate for the caddy in those circumstances is 10% so it doesn't take a mathematical genius to figure out how nicely Byrne has done from those two tournaments alone. Sure, the money is nice. It enables him to travel business class "if I think it's worth it".

It's all a far cry from the day 20 years ago when Byrne decided caddying on the professional circuit might be a good way to see the world. His father Cyril, who won the captain's prize at Royal Dublin on the same weekend in June that Goosen and Byrne Jnr captured the US Open, wasn't overly enamoured at the idea of his university graduate son seemingly turning his back on education.

Byrne has found time to pen an occasional column for The Irish Times and a number have just been put into book form. An indication of the esteem in which he is held by his boss is that Goosen turned up at Royal Dublin last night for the launch of the book by Dermot Desmond. All the royalties are being donated to the Multiple Sclerosis Society of Ireland.

Furthermore, Goosen also wrote the foreword for the book and described how richly his caddy had contributed to the Shinnecock win.

"He may have written he was like a duck in water - all calm above the surface but frantically flapping beneath - I saw and experienced only the calm. Precisely what I required from my caddy on that day and indeed any other day."

Byrne worked for, among others, Philip Walton, David Feherty, Scott Simpson, Roger Chapman, Anders Forsbrand, Greg Turner, and then reigning Open champion Paul Lawrie, before teaming up with Goosen at the beginning of this year.

The South African was big time and the demands on his looper would be considerable. If Colin had doubts, they were dispelled by March, at which stage the boss had banked close to $1m without doing anything out of the ordinary on the course.

He has no regrets at passing up on that degree of many years ago. In his own candid, forthright way he insists that "caddying is a pretty good alternative to work. It's not brain surgery. I've been at it now for almost 20 years and I'm now 40. I don't get tired, physically or mentally. You don't lock yourself up in your room every night but you look after yourself. I run a fair bit because carrying a bag around a golf course won't get you fit, it's all stop and start. I suppose it can be a lonely life but we're all loners and mavericks to some extent and I am happy by myself. Of course I like company and I share rooms from time to time but only with the right people."

Colin Byrne is no golfing bore. Having spent from dawn to dusk with some of the game's finest practitioners, he likes to get away from it all. That would normally mean avoiding your boss but that's not the case in the Byrne-Goosen relationship.

"I have socialised more with Retief than any other player I've worked with," he says.

"But we're only as good as the guy hitting the shot. You never know when you're going to find yourself in the car park again. You never get complacent. Three to four years is the usual time span for the player-caddy relationship. After that, you tend to get sick of each other. You sense when the end is near. I've been sacked. It's the nature of the business - and it works both ways. Caddies also walk away from players."

BE that as it may, there were dark mutterings in the caddyshack last May when Padraig Harrington parted company with Dave McNeilly. It wasn't so much because a successful partnership was breaking up, more that the new man on the bag was Ronan Flood, a friend of Harrington's. Byrne admits he was one of those surprised by the development.

"Eyes were raised and there was talk of nepotism and a bit of resentment," he says.

"That's always the case. When I arrived on the scene, there were about 40 caddies and 140 players. Now there are 200 caddies and 140 players, so it's a player's market. It's a loose arrangement and there's no set format. Ronan's a good golfer and knows what he's doing. Himself and Padraig are doing well. Good luck to him."