The Congressional Country Club stage is now set for what may be a gloriously dramatic or a catatonically dull final round of the Kemper Open.

Fred Couples (68 yesterday) and Scott Simpson (74) are tied at six-under-par 210, one stroke ahead of Tour rookie Tze-Chung Chen (69) of Taiwan. Only one other player is in red figures, fading Tom Kite (76) who bogeyed the last three holes to finish at two-under-par 214.

Behind them, at even par, are the four players with the long-shot chance to make this tournament genuinely special.

Most conspicuous is Craig Stadler who, after a 69 that included an infuriating, momentum-killing water-ball bogey at the easy par-5 10th, now has a remote but plausible chance to become the fifth golfer in 50 years to win the same event three consecutive years.

If Stadler could shoot the kind of 67 that he seemed to have patented here the past two years, he could put considerable pressure on a group of leaders who are exceedingly unaccustomed to their current exalted position.

Tied with Stadler at 216 are 1980 champion John Mahaffey, streaky Andy Bean, always capable of a low round, and long-suffering George Burns, who has inflicted rounds of 77 and now 75 on himself after his record-setting 64 on Thursday. Also at 216 is South African Nick Price. "It's going to take something around 66 for one of us to make a serious run," said Burns.

Should a couple of the Tour's well-known names from the Kite-Stadler-Mahaffey-Bean-Burns group make a hard charge at the interesting but little known trio of players in the final group, this Kemper could catch fire. After all, on Friday Simpson gained nine strokes on first-round leader Burns and yesterday Couples gained six strokes on second-round leader Simpson, so the precedent is there.

However, the Couples-Simpson-Chen trio could have the day to themselves and that, to all but a few golf cognoscenti who appreciate the game for its skills, not its marquee glamor, could mean a day of solid golf but little excitement.

"I like that scoreboard the way it is," said Simpson. "The farther behind those guys (the name players) are, the better. You've got to say that the odds are one of us (in the final threesome) will win it."

Promoters have nightmares about final rounds of $400,000 tournaments where the day's last group of players comprises three gentlemen as little known to the general golfing public as these.

The 23-year-old Couples is a genuinely colorful long-hitting character who seldom strikes a practice shot but lives on the practice-putting green because he's convinced that the PGA Tour is one never-ending putting contest. Despite his flair, Couples has not yet won a tournament.

The efficient and cheerful Simpson, who has won nearly half a million dollars in five seasons, epitomizes the successful but inconspicuous Tour pro who has made a lucrative livelihood out of cashing inconspicuous checks, but who admits he has no burning desire to be great. He's won only one PGA title and did a fairly convincing imitation of a man on the verge of retreat this afternoon as he played the day's final seven holes in two over par and said both his woods and irons were displaying erratic behavior.

Chen is an ebullient type with a winning smile, like the one he flashed after sinking a 30-yard wedge shot for a birdie at the 211-yard 16th hole.

Also, Chen says that he would like to be called "T.C." as a gesture of friendship toward American audiences who have a hard time remembering or pronouncing Tze-Chung. Nonetheless, it is hard for a mass audience to empathize with a rookie who, charming as he is, still speaks little English and, even with a translator, says, "I really do well this week and this week I play very well. I like this course and I putt very well."

Among them, Couples, Chen and Simpson have entered nearly 200 PGA Tour events and have one victory, Simpson's triumph in the 1980 Western Open at long, difficult Butler National. In fact, of the three, only Simpson has ever held a third-round lead before, a five-shot margin at the Western. Couples thinks that "sometimes, somewhere" he had a piece of a third-day lead, but the record book disagrees.

The refreshing Couples is so candid as to say of his previous experiences when he's been close to the lead on the final day, "I've screwed up a bunch of times . . . But that's what you come out here to do, to get in the hunt . . . I've never won and if I don't tomorrow, I'm not going to get all upset."

Should Couples, who has finished 53rd on the money list in his two Tour seasons, win the $72,000 first prize, he could develop into quite an off-beat favorite.

He would just as soon do most everything differently than the majority of predictable Tour pros. "I don't really mind where I hit it," says Couples, which is fortunate, because he drives it everywhere. "Hitting balls (on the range at tournament sites) doesn't do a lot for me . . . Out here, it's a putter's game and that's about it . . . Right now, there are 15 or 20 guys out on the range hitting balls and talking and analyzing each other. But they're just going through the motions. I'd rather practice putting. It's all putting."

As proof, Couples has the third-highest percentage of "birdie conversions" on Tour; that means that when he hits a green in regulation he makes his birdie putt 30.2 percent of the time. If Calvin Peete could do that, he might win them all.

Couples has been scrambling all week and plans to continue in that vein.

"You can't shoot 68 on this course. But sometimes you happen to do it anyway," said Couples of his 68 in which he sank par putts of 20, 15 and 30 feet at the fourth, fifth and 12th holes.

Couples also saved par with a blast from the back bunker at the 16th and made birdie putts of four feet or less at the sixth, ninth and 10th (all par-5s), and the classic 18th where he dropped an eight-iron shot four feet from the hole.

Oh, yes, he sank a 35-foot birdie putt at the eighth.

No doubt today's crowds would not weep if a Walrus or a Kite or a Bean or an ("Oh, God") George Burns or a gritty Mahaffey came out of the pack to rattle the folks at the top whom they haven't yet learned to love.

If any trio ever looked prone to catching the contagious shakes, it's the likeable fellows who tee it up in the final group at 11:55 a.m.

If this day's third-round leaders follow the example of the previous two days and head backward on Congressional's exacting track, then the 72nd hole of this Kemper Open could look like a stampede for glory. Or, if Stadler's involved, a waddle toward history.

If not, bring plenty of suntan oil and a good book. SCHEDULE/ADMISSION

Today: 9 a.m.--Final round. $15, $22.

CBS will televise live today (2:30 to conclusion or 7 p.m., whichever comes first). Children's tickets (grounds only) are available for $5 daily, if child is accompanied by a paying adult.