Graeme McDowell knows how quickly it all can change on Sunday at the U.S. Open.

McDowell was three shots behind going into the final round at Pebble Beach two years ago when he watched Dustin Johnson hit wedge toward the second green and take five more shots for a triple bogey. Just like that, the lead was gone, and so was Johnson. He closed with an 82.

McDowell was in the final group against this year at The Olympic Club, only he had company. Not only was he tied with Jim Furyk, but 11 others were within four shots of the lead.

"It doesn't feel much different than two years ago," McDowell said Saturday night. "I guess I know what to expect now. That's probably the only difference. Emotionally, I went through the same experience today like I did two years ago. I was anxious and I was nervous. Two years ago, Saturday was a tough day for me. And hopefully tomorrow, I'll know what to expect for the day."

For a U.S. Open, expect anything.

Olympic has no water hazards, one fairway bunker and only two players under par. The bogeys come from getting out of position off the tee and even on the greens. The higher scores come from players unwilling to take their lumps after a poor shot.

History has not been kind to the leaders over the last decade.

Rory McIlroy was different, but he was playing a different kind of U.S. Open at Congressional, which was soft from rain and yielded a record score. Throw out his 69 in the final round, and you have to go all the way back to Tiger Woods at Pebble Beach in 2000 to find a 54-hole leader who broke par.

Aaron Baddeley had a two-shot lead going into the final round at Oakmont. He three-putted from 8 feet for a triple bogey on the opening hole and shot 80. Retief Goosen was going for his third U.S. Open title in five years at Pinehurst in 2005 when he took a three-shot lead into the final round. It was gone in three holes and he shot 81.

Such a closing round would not seem likely for McDowell and Furyk. Not only are they U.S. Open champions (then again, so was Goosen), they have controlled games and toughness that makes them equipped for a fight against par.

"It doesn't have to look or be fancy. It has to work," Furyk said. "And I think we have styles of games where we put the ball into play, we put the ball on the green and take our chance at the putt and then move on."

Even so, McDowell was more interested in looking behind him on the leaderboard instead of ahead to another Sunday celebration.

"It's wide open," he said. "I look at guys a 2- and 3- and 4-over par in this tournament, who I really think have a realistic shot to win," he said. "There's a fine line on this golf course between 67, 68 and 75, 76. There really is. It's a tough course. You've got to execute shots well. You've got to keep the ball on the correct side of the pin. And you've got to play well."

There's an eclectic mix of players in range.

Ernie Els is a three-time major champion. Lee Westwood is desperate for his first. Blake Adams is playing in his first U.S. Open. John Peterson, the NCAA champion from LSU, is a year removed from college. Beau Hossler, the 17-year-old wonder, still has another year of high school. Nicolas Colsaerts of Belgium can overpower a golf course. Jason Dufner, a two-time winner this year, prefers to plod his way around.

Not to be entirely overlooked is Tiger Woods, though he has never come from behind — five shots, in this case — to win a major.

And then there's the history of Olympic Club, that doesn't bode well for the favorites.

The winners of the four U.S. Opens at Olympic — Jack Fleck, Billy Casper, Scott Simpson and Lee Janzen — have a combined seven majors. The guys who finished second to them — Ben Hogan, Arnold Palmer, Tom Watson and Payne Stewart — collectively won 27 majors.

Perhaps that's why Olympic is known as the "graveyard of champions," that and the fact that Hogan, Palmer and Watson never won another major after their close calls at Olympic. The exception was Stewart, who won the U.S. Open the following year, but then perished in a freak plane crash that fall.

As the third round was headed for a conclusion, McDowell and Furyk showed their mettle by making key pars and a late birdie. Westwood had finished his 67, and then Els came through a 68 to get into the mix.

Suddenly this U.S. Open had its version of Hogan and Watson and Palmer.

But as the possibilities started to expand, that brought forth another question. Who's going to be Jack Fleck?