If history has anything to teach us about the US Open golf championships here , it is that this week's rendering will prove itself historic. All five previous Opens at Oakmont Country Club in suburban Pittsburgh have been memorable (only Baltusrol, in Springfield, N.J., has staged six). . .
* In 1927, the legendary Tommy Armour birdied the majestic finishing hole and then beat Harry Cooper in a playoff.
* In 1935 Sam Parks pulled off probably the greatest upset ever in the Open. The unknown local club pro was the only man to break 300.
* In 1953, exactly 30 years ago, Ben Hogan won at Oakmont in the midst of his finest season. He also won the Masters and the British Open that year, the latter in his sole attempt.
* In 1962, a chubby rookie won his first professional tournament, defeating crowd favorite Arnold Palmer from nearby Latrobe in a playoff. It was a harbinger of triumphs to come; the youngster's name was Jack Nicklaus.
* In 1973, Johnny Miller shot a record 63, eight under par, in the last round to come from six strokes behind and stun the field and the fans. He hit every green and didn't have to sink any long putts.
Now, 10 years later, the Open is a tournament without a favorite. Seldom has it been so wide open.
Tom Watson, the defending champion and golf's perennial player of the year, has not won a tournament in 1983 and is nowhere to be found among the top 20 money leaders. He took the last two weeks off to work on his game at home in Kansas City.
Watson, of course, made dramatic history of his own last year in the Open at Pebble Beach when he chipped in on the next-to-last hole to deny four-time champion Nicklaus his 20th major championship.
''I'm not in a terribly confident frame of mind right now,'' Watson says.''But then, I wasn't last year either. I've been trying to get more comfortable setting up to the ball and I've been working on my grip, to get my hands more on top of the club and hit the ball higher.
''In this Open, I like players who can hit the ball high. The greens are so firm and fast, you have to land the ball softly to have a birdie putt.
''I played an exhibition round with Jack Nicklaus last week, and his iron play is sharp. If he can make some putts, he'll contend.
''Lanny Wadkins, the leading money winner this year, hits the ball high and played well here in '73. Craig Stadler, Tom Kite, and Hale Irwin play well in the majors.
''Seve Ballesteros won at Westchester last week, and the course was set up very much like an Open course. He has to be given a good chance even though he's never played well in the Open.''
Ballesteros, the Masters winner on a wide-open Augusta National layout, is taking confidence from his Westchester victory Sunday, when he eagled the last hole to edge Fuzzy Zoeller and Andy Bean.
''Westchester was narrow fairway, thick rough, and pretty fast greens, similar to the US Open,'' he said. ''I have a chance, though Open courses aren't the best for me because I miss a lot of fairways. I've never played Oakmont, but I know how the US Golf Association puts a course for the Open.''
Oakmont is hard enough without a lot of help from the USGA. Day in and day out, the greens may be the most difficult in golf, and good players have been known to four-putt and even five-putt.
Nicklaus, playing a practice round last week, putted the ball from the back of the second green all the way down off the front. ''I love fast greens,'' he says. ''But some of these are almost unreasonably fast.''
Sam Snead once told the story of marking his ball on an Oakmont green with a dime - and watching the dime slide several feet.
The greens are uncommonly difficult. But that doesn't make the rest of the 6, 972-yard course easy by comparison. The fairways are tight, the rough is lush from extensive spring rains, and some 178 bunkers come diabolically into play from the first tee to the 18th green.
It was the belief of the architect, steel magnate H. C. Fownes, that every mistake should incur a penalty, and Oakmont is one of the most penal inland courses in the world. There is not a drop of water in play, but the existing hazards are quite torment enough.
Miller's 63 a decade ago stunned the Oakmont membership, which prides itself on playing a monster of a test, and the club has been toughening the conditions ever since. For this year's Open, many of the greenside bunkers have been quietly deepened.
''It's as tough a test as there is,'' says defending champion Watson. ''Once I got here, I began spending a lot of time getting used to the greens, because they represent the ultimate challenge here. You can just touch the ball and see it roll 40 feet.''
Symbolically enough, the big practice green takes up the back half of the ninth green and occupies center stage in front of the grand old clubhouse.
''It will be a challenging week,'' sums up Watson. ''That's the way it should be. The USGA rightly says it isn't trying to embarrass the best golfers in the world in the Open - it's trying to identify them.''