Gary McDowell, Graeme McDowell, Rory McIlroy and Gerry McIlroy prepare to fee off for the second round of the 2011 Alfred Dunhill Links Championship. Picture, Stuart Adams, www.golftourimages.comIt’s hard to know which is the bigger story - ‘Rory McIlroy ditches Chubby Chandler ’ or ‘Boutique Irish management company lands another US Open champion.’

The news, broken to Chandler by McIlroy in JFK airport on Wednesday night, came as a shock to the ISM founder. In truth, neither McIlroy’s exodus nor Horizon’s elevation to global player should come as a huge surprise to anyone.

Lee Westwood tweeted: “Bizarre decision!” But in truth, it’s Westwood’s strange “banter” with McIlroy and his less than sporting comments during the Masters and the US Open that have been truly bizarre.

Whatever about McIlroy’s standing in an ISM stable dominated by Westwood and Clarke, sources close to industry say he has been planning the move for several months.

And co-incidence or not, the fact remains that Chandler has lost three high profile clients since the end of last year - Paul McGinley, the potential 2014 Ryder Cup captain, Ernie Els and McIlroy. That’s a lot of money walking out the door.

But that won’t bother Horizon, which has been quietly making a name for itself since it signed McIlroy’s close friend Graeme McDowell from Chandler’s ISM group in 2007 and Ross Fisher from management giants IMG in March 2009.

Founded on the strength of a re-mortgaged home in 2005 and boosted by outside investment four years ago, many will raise doubts over the ability of Conor Ridge’s six-year old company to after the affairs of one of sports most marketable assets. But McIlroy has seen at close hand what Horizon has done for McDowell.

Similar fears were raised for McDowell’s future when he left Chandler as a frustrated and disillusioned player four years ago (“Let’s see how many deals he gets” was one reaction from ISM people.) Yet the sponsorship deals have rolled in without too much difficulty. McDowell won twice with ISM. With Horizon he has six wins, including the 2010 US Open, not to mention two Ryder Cup appearances and new deals with a string of blue chip sponsors.

Chandler was unavailable for comment when we tried to contact him on Friday, though he did speak to Golf Digest’s Tim Rosaforte and the Daily Mail’s Derek Lawrenson from Dubai later that evening. According to the Mail:

‘I don’t know whether it was his girlfriend (world No 1 tennis player Caroline Wozniacki) getting in his ear or someone else but I thought we were doing a pretty good job, to be honest, and I think that’s how the outside world saw it,’ said Chandler.

McIlroy made it clear that is not how he saw it in a face-to-face with Chandler six weeks ago.

‘We sat down and he said he was not happy with his brand, sponsors, website or his public relations image,’ said Chandler.

The outside world included the Irish press contingent, which has had a virtually non-existent relationship with ISM in recent years though the player himself has always been more than co-operative in face-to-face situations.

For some time there has been growing concern in Irish golf circles about the handling of McIlroy. Horizon will have witnessed it all with dismay.

The litany of management missteps came to a head this year in the Twitter row with TV commentator Jay Townsend, an affair that was of McIlroy’s doing but something that could surely have been handled more adroitly by his management company.

Just last month, Chandler hinted that McIlroy might just skip next year’s Irish Open to play in the AT&T National at Congressional, site of his US Open win last June. He may well feel that the Irish Open is small beer - an impression reinforced by his attitude at this year’s event - but that’s a public relations nightmare waiting to happen for an Irish golfer.

If ISM had a career strategy in place for McIlroy, it appeared to change every 12 months. And it became abundantly clear that it was McIlroy who was calling the shots.

As Chandler said in frustration when speaking of the tree-root incident at the US PGA and calls for a change of caddie: “He doesn’t listen to anybody. He won’t listen. All this about having a new caddie is all bullshit because he won’t listen.”

It wasn’t the first time that McIlroy decided to ignore advice from his team.

At the WGC-Accenture Match Play in Arizona in February 2009, Chandler said: “There’s absolutely no point in him taking out his PGA Tour card. Suddenly he has got to play 15 tournaments. Suddenly they start dictating to you.”

McIlroy had just won his first event as a pro in Dubai. But by November he’d decided he was going to play on the PGA Tour in 2010 and Chandler was not best pleased.

A disappointing year later, McIlroy said he was homesick and changed his mind.  But just a few months ago, he changed his mind again and United States, where Horizon has been setting up a base this year, is now his destination for 2012.

It all sounds vaguely familiar to Irish ears. McDowell’s ill-fated sojourn to the US and his subsequent failure to make the 2006 Ryder Cup team in Ireland accelerated his decision to leave Chandler’s burgeoning stable.

Graeme McDowell and Conor Ridge at this year’s US PGA in Atlanta. Picture Fran Caffrey www.golffile.iePart of the reason he left ISM in 2007 was the sense of neglect he felt at the English based company. He was a small fish in a big pond - a pond dominated by big fish called Westwood, Clarke and Ernie Els.

McIlroy is no small fish, but he was always going to be the new kid on the block in a stable that was built around Clarke and Westwood - the alpha dogs.

McDowell explained exactly why he left Chandler in November 2007 and his words are remarkably similar to those used in the statement attributed to McIlroy on Friday:

“I have had a great relationship with ISM over the last five years and they were the perfect fit for me in the beginning.

“But things were stagnating a little bit as far as my career went in terms of motivation and interest. I wanted to freshen thing up and get a boost of energy really.

“Stale is probably the only way to describe it. ISM have been going through some really big changes the last couple of years with some big acquisitions like Ernie Els and guys like that.

“A few months ago I told Chubby that I was a little disillusioned with what was going on and felt like I needed a change.

“I like what’s going on with Horizon. They are young, they are ambitious and energetic and I feel they are a really good fit for me.

“I feel like I have got a great team of people around me now and this move was the last little piece in the puzzle.”

Time will tell if McIlroy has made the correct decision. He has been friends with Ridge since he turned professional. Why wouldn’t he be pals with the ever-present manager of McDowell, his best friend on tour and the man who helped him through the controversy surrounding Tiger Woods at the 2010 Ryder Cup?

Friends talk and relationships grow over the months and years. And while ISM was juggling his affairs of 26 players - including Westwood and major winners Clarke, Louis Oosthuizen and Charl Schwartzel - a young Ulsterman was making decisions.

When Horizon make the official announcement remains to be seen. No-one at the Dublin company was returning calls yesterday.