Ben Crenshaw, the leader at the midpoint of the 61st PGA, knows all the stories about Oakland Hills and the nooks and crannies of golf history that have been made here in four US. Opens and one previous PGA.

Gentle Ben, who burned up the tour as a 21-year-old rookie, yet now faces the possibility of a mildly disappointing career at 27, can recite the exact progression of scores on the merciless 10th hole that cost Bobby Jones the Open here in 1924.

"Buzzard (British for double bogey), bogey, buzzard, buzzard," said Crenshaw, discussing the fine points of now Jones' mashie (five-iron) betrayed him in the final round.

"Cyril Walker won in '24 ... yes, I know all the tales of every tournament here ....Ben Hogan, Gary Player, Gene Littler," said Crenshaw after his 67 today gave him a four-under-par 136 for a one-shot lead over Rex Caldwell, Jay Haas and David Graham, and a two-shot edge on Tom Watson, Alan Tapie, Jerry Pate and Bruce Lietzke.

"I'm a student of the game, a collector of golf artifacts and old volumes. It's my passion. I'd dearly love to win here on this great test of golf, a course with so much history ... I'd give my eye teeth for it."

Ben crenshaw also knows his own painful history, one which he may slowly be correcting. After announcing himself by winning his first pro event, on top of a masterful amateur career, Crenshaw has settled down to a steady diet of weathly but fundamentally unsatisfying seasons.

Once, in 1976, he was the tour's No. 2 money winner with $257,759. But in his other five years he never cracked the top 15. As for the majors, Crenshaw is the man who comes oh-so-close , then fizzles at the end.

"Maybe I try too hard in the major tournaments just because it is such a passion for me .... I don't know," said Crenshaw, who has finished second in the last two British Opens, and ended just one stroke back at the 1975 US. Open after splashing a tee shot at the 71st hole.

"I believe you have to knock on the door of the majors before you can get in," added Crenshaw, whose score today was just one of 18 sup-par rounds led by Tapie's course-record-tying 65 as the Hills continued to play wet and easy.

"I won't say that I deserve to be let in yet," added the gentlemanly Crenshaw with a smile. "Let's just say I want to be in a position to knock against when that final nine holes starts on Sunday."

Although Oakland Hills, with its rough scraggly and stamped down, its greens soft as a dart board and slow, and its wet fairways keeping shots from kicking into the rough, was playing about as tough as the old Quad Cities Open, many a big name came to grief.

Jack Nicklaus, Andy Bean, and Fuzzy Zoeller at 145 and defending champ John Mahaffey ar 146 and defending play the back nine worrying about making the cut (146) rather than winning the tournament.

Hale Irwin (148), Tom Weiskopf (150) and poor Arnold Palmer (155) wished they had such problems.

"I keep thinking I can play better, but it's only a figment of my imagination," said the 49-year-old. "I just can't put it together. I should have just withdrawn before the tournament started. I won't be shooting many more 80s, I guarantee you that .... I can't go on like this."

Ageless Sam Snead goes on and on, though. Snead shot 71 for 144, not bad for a 67-year-old.

It is much more fun to be young. Tapie shot his 65, which tied Ben Hogan's competitive score for the course, without even noticing it.

"I chipped in for a birdie at 18 and all of a sudden I had a 65," he said. "I sure didn't know it was the record."

As for Crenshaw, he felt certain that the four-round course record of 281, established in those other years when Oakland Hills was not the victim of rains that pulled its teeth, would be shattered by gangs of golfers.

"Four consecutive sub-par rounds is not an unreasonable thought" said Crenshaw, knowing that in 2,100 previous major tournament rounds here, only 49 sub-par scores had been recorded. "I missed a lot of good putts, or I don't know what I'd have shot.

"I know I've been followed by a lot of expectations over the years," said Crenshaw, "but I can't blame my disappointments on that.

"Last time I looked, I was the one holdin' the clubs. I've got no one to blame but myself."

First-round leader Watson, who had to battle for his 38-34-72, knew where the blame lay for his miseries -- in his driver.

"Obviously, I didn't use my new swing-thought as well as I did yesterday," he said. "I drove it into five fairway bunkers -- four right and one left.

"If you'er in there you'er dead. I'm not upset. Some days you have it, some not. I'll get my rhythm down a little better and be fine.

"The winning score will probably only be two or three under par . . . you watch," said Watson, as Pate agreed. Watson continued: "This course can grab you, especially if the wind keeps blowing and drying everything out. Conditions will get harder and tougher every day and people will start backing up."

While Crenshaw was delighted, the three pursuers in second seemed a bit nonplussed.

"I've always been disappointed because I've played terribly in major championships," said Graham, an Australian who looks perpetually haggard as though just returned from a three-day kangaroo hunt. "I've never understood it, because my game -- accurate driving and long irons -- would seem to be suited to the majors."

Most surprised at his position was the charmingly blunt Caldwell, who said his 70 today was "a whole lotta hard work with 10 putts of four feet . . . every one of 'em knee-knockers.

"I had to wait 'til 2:30 p.m. to tee off and it felt like I didn't hit a ball until Saturday. I just watch Laverne and Shirley and the Brady Bunch and The Tower of Power ... all that junk, anything to keep from thinking about what I had to do."

Once on the course, Caldwell's day was constant adventure, a total contrast to his opening 67 when he missed only one fairway and one green. "I was on cart paths thinking, 'If I flinch I just bought myself an instant 'double.' I was pickin' it dead perfect out of all kinds of garbage, then draining the lttle ones for par."

Reminded that many an unknown had followed just such a progression before disappearing from contention, Caldwell grinned and said, "Oh, you can book that. This thing is a mind trip.

"It's always been my goal just to win one tournament -- any tournament. I wasn't even thinking about a major. Hey, it would take care of a lot of my business to win this tournament." CAPTION: Picture, Alan Tapie finishes a course-record-tying 65, a mark set by Ben Hogan, at the Oakland Hills Country Club layout. UPI