US OPEN: Who will conquer Congressional?

Four players have taken their turns at No. 1, the highest number between U.S. Opens in the 25-year history of the world ranking. Four players won their first major in the last 12 months. Four others captured their first World Golf Championship.

And it's largely because of a guy who's not even playing.

The presence Tiger Woods brings to golf is felt even more strongly in his absence.

Woods will not be at Congressional, missing the U.S. Open for the first time in 17 years because of lingering injuries to his left leg. Some could argue he has been missing for the last year as he has tried to mend his personal life, his health and his golf swing. He has gone 18 months without winning, paving the way for a new generation of stars to emerge.

And they have.

Graeme McDowell started it off by winning the U.S. Open at Pebble Beach, and he peeled back a massive layer of Woods' mystique at the end of the year by overcoming a four-shot deficit in the final round and beating him in a playoff at the Chevron World Challenge.

Louis Oosthuizen (British Open), Martin Kaymer (PGA Championship) and Charl Schwartzel (Masters) - all of them in their 20s - won the next three majors. Lee Westwood ended Woods' five-year stay atop the world ranking, and Kaymer and Luke Donald since have gone to No. 1 in the world over the last four months.

None of that seemed possible when Woods was on top of his game, dominating to such a degree that he won nearly 30 percent of his tournaments and made it look as though no one else had a chance.

Are players getting better? Or were they always this good and no one noticed as long as Woods was winning so often? Maybe it takes Woods being gone to realize just how good he was.

"Some of the younger players came along when Tiger was on a tear, and they were in his shadow," Mark O'Meara said. "He was bigger than life. But now that Tiger is somewhat removed from the game, they've been able to shine."

With the absence of Woods - and to a lesser extent, Phil Mickelson, who has only one win in the last year - the new landscape in golf features parity not seen in some 20 years. When the 111th edition of the U.S. Open begins outside the nation's capital in Bethesda, Md., no one stands out as a clear favorite.

"Tiger has been the dominant player in this generation, really since the mid-90s," Stewart Cink said. "Eventually, he won't be anymore. Maybe that's already happening - we don't know. He won so many tournaments, maybe there were just less available to win."

That sounds like Colin Montgomerie's theory from years ago on why it was so hard to win majors. Montgomerie reasoned that Woods was winning two a year, leaving only two majors for everyone else.

Now, they're all up for grabs.

Ten players have won the last 10 majors. Only two of those players, Mickelson and Angel Cabrera, had won before. The last time Woods had to skip a major, because of season-ending knee surgery in 2008, there was debate whether an asterisk would be placed next to the winner's name because Woods wasn't in the field.

There will be no talk of an asterisk at Congressional.

Even if Woods were around, this U.S. Open lives up to its name - open.

"Anybody can win," Davis Love III said. "You can't say it's going to be either Tiger or Phil or (Jim) Furyk or Luke Donald. It's wide open. It's like when Greg Norman was the favorite and everybody looked to him. I don't know if you can pick a favorite for the U.S. Open."

The U.S. Open is known as the toughest test in golf, and the challenges come from all over. The fairways are narrow, the rough tends to be thick, the greens as firm as any all year. Par tends to be a good score at the U.S. Open, and par can sometimes feel like a birdie.

McDowell won at Pebble Beach last year at even-par 284. Four of the last six U.S. Open have been won at even par or worse.

"I know I'm going to have to prepare myself for the feeling that I am playing badly, even when I'm not," former U.S. Open champion Geoff Ogilvy wrote in a column for Golf World magazine. "I have to convince myself that par golf - or even 1 or 2 over - is good. It's just so different from any other week on tour."

Even the golf course is different from the last U.S. Open at Congressional in 1997, won by Ernie Els.

The closing hole was a par 3, which proved to be anticlimactic. The championship effectively was decided on the 17th, when Montgomerie stood forever over a 5-foot par putt before missing it, and Tom Lehman in the last group pulled a 7-iron into the water. Rees Jones again has tweaked the course, and the 17th hole from 1997 is now the 523-yard 18th hole.

The old No. 18 has been flipped around, and now is a daunting par-3 10th.

Players champion K.J. Choi, Anthony Kim and Woods have won at Congressional in the three years it hosted the AT&T National. That might not mean anything with the course set up as a major.

The best bet might be someone from outside the United States.

For one thing, out of all the majors, Americans have had the least success in their national open over the last 10 years - just four wins, with two of those by Woods. International players have won the last four majors, and another victory would mark the longest drought in the majors for an American since the Masters began in 1934.

And perhaps even more troublesome for American players - they have been shutout of the top three in the Masters, British Open and U.S. Open dating to last year.

The headliners, if there is such a thing these days, would start with the guys at the top of the ranking.

Donald has finished in the top 10 in his last 10 tournament worldwide, and his chipping and putting would seem to be a good fit for the U.S. Open. Westwood has the most experience contending in a major, even though he hasn't won yet. It was only three years ago when he stood over a 15-foot birdie putt on the last hole at Torrey Pines to get into a playoff, only to leave it short.

He also missed a par putt that kept him out of a playoff at Turnberry, and he lost a 54-hole lead to Mickelson at the Masters.

American golf is not as bad as it might seem at the moment. Finishing off majors is a different story. A year ago, Dustin Johnson had a three-shot lead going into the last round and shot 82, the highest score in the U.S. Open by a 54-hole leader in nearly 100 years. Nick Watney had a three-shot lead at the PGA Championship last year and shot 80.

That's not exclusive to Americans, though. Rory McIlroy of Northern Ireland had a four-shot lead going into the final round at the Masters this year, and the 22-year-old closed with an 80.

"I don't know how Dustin and Nick were feeling whenever they were going into the last round leading, but it's a new experience," McIlroy said. "They're major championships, and you want to really try and get your first one out of the way and kick on."

McIlroy's mistake eventually allowed Schwartzel to win. Johnson's blunders gave way to McDowell, while Watney's blowup in the PGA Championship ultimate set the stage for Kaymer to win in a playoff over Bubba Watson (only after Johnson was penalized for a bunker he didn't know he was in). All of them are young, all were new to major championship experience.

Such is the way golf is going at the moment, especially with Woods not much of a factor on the golf course - and not a factor at all as long as he's at home trying to heal himself.

"Will he be back? Nobody knows at the minute. There's obviously a lot going on," McDowell told Sky Sports News. "His mental health is one question and his physical health is now another. Golf needs him. He has been golf for the last 15 years."