AS BEFITS perhaps the best course in England, there are 18 good holes on Royal Birkdale. It really is hard to pick out a weakness on this wonderful course. But, inevitably, some holes are more influential than others. Here are the four I feel will make the difference between winning and losing, when the identity of the 'champion golfer of the year' is decided today...

6th: 499 yards, par 4
This is an influential and pivotal hole simply because it is so hard. You can make a six or a seven here without hitting a really bad shot. In practice earlier this past week it was playing maybe a driver and a long iron to the green. Which was fine. Then, come Thursday morning when I was unlucky enough to be playing, the hole turned into a monster. It was a three-shot par-4.

I was playing with Davis Love and Oliver Wilson. None of us hit the fairway and I ended up closest to the green in two shots, from where I needed a five-iron to reach the putting surface. The problem was the tee; it was probably a bit too far back. Which was a shame. This would be a better and more interesting hole with the tee moved up. As it was on day one, the bunkers were completely out of play. The ideal scenario would be to tempt us into trying to carry the bunker on the right. But that, of course, is difficult to achieve on any given day.

It is hard to imagine anyone making a birdie here. But six or seven are possibilities. There is thick rough all over the hole. And if you do find sand from the tee, it is tough to get up in three. Then there is the green. The slope at the front is severe; a lot of balls run 25 yards back down the hill.

12th: 184 yards, par 3
This is a really good par-3, perhaps the best of Birkdale's four short holes, and one that normally plays longer than its yardage, especially when the wind is blowing against and from the right. It's a classic links hole really, with a cool-looking green set dramatically into the distant hillside.

The normal tendency here is to miss to the left, the ball tending to run down into a little gully, if only because anything right of the green is almost certainly going to lead to a bogey or worse. In fact, as little as five yards from the back-right flag position is death. It's a tiny target really, one where it is better to be long than short.

There is hardly any room between the two bunkers front right and left, but the green opens out past those two hazards. All of which makes 'middle of the green' a smart play no matter where the wind is blowing. It's my guess that whoever is leading standing on this tee will gladly accept a par, never mind what his challengers are doing.

The upside is that this green always gives you hope. With the banks on both sides, there is always a chance that a slightly errant shot will kick back towards the flag. So this is a real 'swing ' hole, one where a player could arrive two shots ahead and leave five ahead. Or, of course, see a two-shot lead turn into nothing in a heartbeat.

15th: 544 yards, par 5
This is one hole where the luck of the draw can make a lot of difference. On day one I hit my best drive and a pretty good three-wood 90 yards or so short of the green. A few hours later, my friend and compatriot, Adam Scott, was able to reach the green with his second shot. Adam is a little longer than me – but not that much!

Anyway, that factor should be less important today when the leaders will all be playing at the end of the field. They will all be playing the same hole, more or less.

And what a hole it is. Off the tee, you will see most players attempting to draw the ball off the right side of the fairway. The fairway seems to set up well for that shot, which normally goes farther than a fade anyway. It's vital to hit the fairway though. If a player misses the short grass – which is comfortably wide – he is going to be faced with some tough decisions.

The first of those is whether or not to attempt the carry over the cross bunkers that lie maybe 170 yards from the green. That's a tricky shot, especially if the lie in the rough is less than perfect. Even the lay-up is no bargain. The gorse on the right of the fairway is right in play if the shot is pushed even a little bit. So a poor drive inevitably leads to all kinds of trouble.

17th: 572 yards, par 5
You have probably been reading a lot about this hole over the last few days and, if you have been viewing the Open on television, watching the players suffer on and around the eccentrically-designed putting green. First things first, though. Normally downwind, the tee-shot here is pretty straightforward. Like most players, I have been hitting a three-wood to stay short of the bunkers up the right side. Only if the wind is really strong would I consider trying to hit a driver over the corner of the slight dogleg. Although that would leave me with only a short iron to the green, there is obviously more of a risk involved.

The success or otherwise of the second shot is largely threatened by a pot bunker that sits in the middle of the fairway, maybe 30 yards short of the green. Especially if the wind is really blowing and the ball has to be pitched short and run up, it is right where you want to land your shot. It's a well-positioned hazard, one that makes you think.

The green, however, is pure Disneyland. I hear that one player called it a skateboard park earlier this week – and he isn't far wrong. It slopes all over the place. Which is fine up to a point. But this putting surface has little or nothing in common with any of the other 17 here at Birkdale. It is out of character and has the potential to undo a shot that should not be punished severely.