GOLF:AS SOMEONE once remarked, "the very act of believing creates strength of its own". The anonymous philosopher has a believer in Rory McIlroy. Yesterday, on the eve of the BMW PGA Championship here at the Wentworth Club in Virginia Water in leafy Surrey, the 23-year-old Ulsterman – the world number one and seemingly pre-tournament favourite every time he tees up a ball – didn't so much as bat an eyelid or raise his eyes to the heavens when asked when he started "thinking" he was the best player in the world.

“There’s a difference between thinking you had the potential to be the best player in the world and then actually (believing). I’ve always believed in myself. Maybe Congressional last year (the US Open win), after that I started thinking of myself as definitely one of the elite players. I think I moved up to number three in the world at that point. From then, I’ve played pretty consistently, won a couple of times.

“You know, I’ve always believed on my day I can beat anyone else. It’s hard to walk around saying I’m the best or whatever, but you just have to believe in it and be quietly confident,” replied McIlroy, adding: “You have to believe that you’re the best and I certainly do believe that. It’s just a matter of going out there and showing everyone else what I believe.”

Such self-belief can be like a 15th club in the bag, and McIlroy – who has had a long-standing relationship with the West Course going back to his pre-teens when he literally ran 36 holes a day during the World Matchplay as he sought to get a close-up view of the tour’s star names – has certainly matured into a player who can turn such confidence into more big wins.

The BMW PGA, his first appearance of the season in Europe before flitting back across the Atlantic for the build-up to next month’s US Open in San Francisco, is, nevertheless, a serious examination. Luke Donald, the holder, could further extend the yo-yoing atop the world rankings if he were to win here, while world number three Lee Westwood, beaten by Donald in a play-off a year ago, has also set his sights on adding the tour’s flagship event to his CV. In all, eight of the world’s top-20 ranked players are in the field.

And Justin Rose, already a winner on the US Tour this season, put it succinctly about what winning the European Tour’s flagship would mean. “It’s on my bucket list,” he said. His and many others, for that matter.

Yesterday, Donald – who needs a win to overtake McIlroy at the top of the rankings – admitted that, although McIlroy’s keenest rival, he was able to stand back and admire the Ulsterman’s swing. “I think Rory is one of the most naturally-gifted players there is. He has that look about him, free-flowing. He hits the ball far, (and) just seems really effortless.”

The admiration society has a tough edge too, as you’d expect from players who deem success by the amount of titles won and, especially, in the haul of Majors. On that count, as well as the current official world rankings, McIlroy is ahead of the Englishman.

McIlroy’s season to date – which has seen him win the Honda Classic in a run that features six top-five finishes, a tied-40th at the Masters and a lone missed-cut in his last outing at the Players – has seen him consistently contend. The aberration of the Players, and a dislike of the Pete Dye-designed course at Sawgrass, shouldn’t affect him as he sets his sights on the European Tour’s flagship event. As McIlroy put it when queried about his record around this West Course – where he has a best finish of fifth (2009) but missed the cut in 2008 and has finished 48th and 24th in 2010 and 1011 respectively – “This is a golf course that I love, a golf course that I came to every year since I was 10 years old to watch the World Matchplay . . .  I have some great memories of this place. I haven’t played that well over the last couple of years but it’s a place that I enjoy coming back to.”

He added: “I really like the changes that they’ve made. I like that they’ve turned the 12th back into a par five. I like that they’ve flattened out a little bit of the side of the 15th green. I love what they’ve done to 18, to take that bunker out on the right and cut down the trees a bit so it’s a much more inviting tee-shot. You can challenge the right side of the fairway and give yourself a chance to hit the green in two.”

Although the trees down the 18th have been trimmed back to entice a more aggressive play down the finishing hole, the West Course – playing to 7,302 yards – is one, as Donald proved last year, that demands accuracy throughout as much as power.

A year ago, McIlroy was so long finished his final round that he was back in his hotel by the time the Donald-Westwood duel only finished in extra holes. Still, a twinkle came to his eyes yesterday as he assessed the possibility of another one-two duel come Sunday.

“You couldn’t have written a better finish for the world number one and two to come down the stretch, tied after 72 holes, (and) play in a play-off . . . it was a great finish, and it would be great if I could be part of a finish like that this year.”

You can bet no one will possess as much self-belief walking onto the first tee as McIlroy. Yet, as this championship as proven down the years, it can throw up quirky winners. Drummond. Oldcorn. Hansen. Khan. Maybe Donald’s win last year will be the start of a trend of world number ones taking the honours.

Over to you, Mr McIlroy.