1st 482 yards Par 4
Downhill off the tee, if you don't hit the ball 290 yards, your second shot with a middle iron is blind to a green that slopes away from you.

Johnny Miller closed with a 63 to win tin 1973, but he doesn't pull any punches describing the test.

Miller said: "No. 1 is the hardest opening hole in the word. If you miss that fairway on No. 1, as they would say - "Forget about it." If you try to go for that green, you're going to make a big number a lot of the time. Just hit it in the fairway, if you have a brain."

2nd 341 yards Par 4
In the 1994 play-off Ernie Els made seven to Colin Montgomerie's six. Some players might be tempted to drive the green, but it comes with great risk. Generally a long iron off the tee to avoid the ditch on the left and bunkers on the right.

The green is severely bunkered and fiendishly contoured. Three putts from above the hole are common.

Sam Snead was playing No. 2 one time and said the greens were so fast that when put his dime down to mark his ball, the dime slid away.

8th 288 yards Par 3
The longest par 3 in major championship history. Some short hitters might have to hit driver. A bunker called Sahara is 100 yards long and sits left of the green.

Tiger Woods joked: "It's pretty nice that you can drive a par-four like that. I've hit wood every day, and it's pretty good for the confidence.

10th 435 yards Par 4
Downhill drive to a narrow fairway with hazards on both sides. Tom Watson double-bogeyed the hole in both the 1983 US Open and the 1978 PGA Championship.

Miller said: "Holes like 1, 10, those holes were designed in hell, okay, the greens, either that or the back part of them fell into hell."

17th 313 yards Par 4
Driveable for some but most players with a nest of bunkers and nasty rough to carry just 50 yards short of the green, most will hit a long iron and leave an 80- yard pitch. But watch out for the cavernous "Big Mouth" bunker on the right.

Woods said: "You can take a cut at it. But the lay-up on the right is no bargain either, because the green is tilted and it's slanted and dried out quite a bit. It's a hole that's going to be probably pivotal and very key to who wins the championship."

(Green speeds)
The greens at Oakmont regularly run at 14 or 15 on the stimpmeter for the members. The US Golf Association has had to slow them down to between 13 and 14 this week.

Yet Phil Mickelson has taken his own steps to make sure he gets the speed of putts exactly right with a gadget designed by his short game coach Dave Pelz - a former NASA scientist

Mickeslon said: "We call it a Pelz-Meter. He spent $150,000 on this computer chip and it has a mathematic computation that allows him to measure greens on any green surface regardless of slope and pitch.

"I know what speed each green is. I had one as fast as 15.6 and one as slow as 11.2 and that's four and a half feet of difference right there. It's important that I have that information going into these greens."

Oakmont Opens
1927
Average score: 78.6
Rounds under par: 2
Purse: $800
Champion: Tommy Armour

1935
Average score: 80.55
Rounds under par: 3
Purse: $5,000
Champion: Sam Parks Jnr

1953
Average score: 77.12
Rounds under par: 20
Purse: $14,900
Champion: Ben Hogan

1962
Average score: 75.86
Rounds under par: 19
Purse $81.600
Champion: Jack Nicklaus (bt Arnold Palmer play-off)

1973
Average score: 75.45
Rounds under par: 40
Purse $219,400
Champion: Johnnie Miller

1983
Average score: 76.13
Rounds under par: 27
Purse: $506,184
Champion: Larry Nelson

1994
Average score: 74.25
Rounds under par: 62
Purse: $1.75 million
Champion: Ernie Els (bt Loren Roberts and Colin Montgomerie play-off).