The biggest weakness of tennis is that it's too fair. The better player wins far too often.

In this sport, the genuine upset is an endangered species. Even here at Wimbledon, where grass is supposed to produce "unexpected" results, the first 10 days of this fortnight have amounted to little more than a foregone conclusion.

Who is in the women's final? Chris Evert Lloyd and Hana Mandlikova, the No. 1 and No. 2 seeds.

Who are in the men's semifinals? Why, Bjorn Borg, John McEnroe and Jimmy Connors, of course, the top three seeds, and the same trio of gentlemen who show up in the semis of almost every event worth winning.

We claim that, at least in sport, we want to see justice done. Give us the truth of the matter, we cry. But even the truth, once it has been demonstrated a dozen times over, can be a bore.

The perfect example this week was the quarterfinal match between Borg and his friend Vitas Gerulaitis.

If Borg and Gerulaitis were, for instance, golfers of similarly close ability, there would be many days, many tournaments, when Gerulaitis would fare better. Why? Because 18 or even 72 holes are a tiny sampling of a golfer's total ability. Luck plays a generous part.

In tennis, luck has been all but eliminated. Gerulaitis played splendidly against Borg, returning unthinkably difficult shots and drawing cheers scores of times. However, in their match, the ball crossed the net far more than 1,000 times. The test of talent, the sampling of shots and strategies were far too complete to give Gerulaitis even a remote chance of winning.

Gerulaitis' ranking by the ATP computer for the last four years has been ninth, fourth, fifth and fourth; he is a genuinely great player. Yet his career match record with Borg is 0-20. He has never won, and, when it really matters, he probably never will.

Tennis buffs like to maintain that, at the very least, their sport is supremely competitive by the time tournaments reach the semifinals.

But it ain't necessarily so.

Wimbledon is the greatest of all tennis, but the men's semis here on Thursday are -- despite all optimistic hope-against-hope -- probably just two more foregone conclusions.

Rod Frawley, this year's interloper in the semis, has -- how can we say this tactfuly? -- no chance whatsoever of beating John McEnroe. Frawley, who has a nice mustache, a friendly smile, a good sense of humor and has never kicked an old lady, knows he's gotten to Centre Court on a fluke of the draw: so he's enjoying his day in the sun (such as it is here) and will, presumably, ask for a cigarette before he puts on his blindfold and steps in front of McEnroe's machine gun.

"I hope to give him some trouble," ventured Frawley.

He wasn't foolish enough to talk of winning. No need to wake up McEnroe. Perhaps, if he lies in the weeds and looks pathetic, he can win a set. Frawley knows whom he beat to get here: nobody.That's n-o-b-o-d-y, spelled Cliff Letcher, Carolos Kirmayr, John Fitzgerald, and Tim Mayotte. Okay, the 20-year-old Mayotte might someday by a top 20 player, once he matures. But he was in his first month as a pro here.

"If he'd used the right strategy, he might well have beaten me," said the honest Frawley. "But he didn't take advantage of things that other players probably know about me."

To be candid, only two things have happened this Wimbledon that would cause surprise among pros themselves. Pam shriver's victory over Tracy Austin (after 11 consecutive pro loses, plus others as a junior) was one of those well-it-had-to-happen-sooner-or-later, but-it-probably-won't-happen-again-for-a-long-time upsets that might merit one raised eyebrow.

Frawley is a two-eyebrow case. Even with an open draw and never a seed in sight, his appearance here Friday is the sort of fresh breeze that tennis lacks; more's the shame that he can't win. Again by contrast, the less severely honest world of golf offers glory days to its Frawleys -- the guys such as Orville Moody or Fuzzy Zoeller who come from beyond the top five, or even the top 50, to win tournaments, and, occasionally, even major events.

The 28-year-old Australian won't get that sort of one-time-only chance to liven his sport by laying his colorful and sympathetic tennis history before his game's fans. There won't be headlines about how he played modest club tennis in Germany until he was 25, teaching on the side. There won't be an instant paperback on how Frawley came from 63rd, 55th and, currently, 115th on the computer list to win Wimbledon.

Frawley's sport is just too fair for its own good. Once one player has learned another, school's out. For instance, the first time Frawley sneaked up on McEnroe last year in Brisbane on grass, he gave him a three-set-scare, losing in the third, 6-4. The next time, "He destroyed me. . . My best part is return of serve. Against anybody who doesn't have a bomb (serve), I have a chance." said Frawley.

McEnroe has one of the biggest bombs of all.

In a more subtle way, the other semifinal -- the glamor pairing of Borg and Connors -- is an even better demonstration of tennis' inherent problem. The Borg-Connors case history is a paradigm of almost all evolving tennis competitions.

The first time they played, in Sweden, Borg announced himself, at age 17, with a victory. Connors' dander got up and he won their next six meetings while he was at his peak and Borg was growing up.

For two glorious years -- '77 and '78 -- Borg had fully arrived, but Connors wasn't ready to step down: Borg had a 4-2 edge in matches, including a Wimbledon final, but Connors beat Borg for revenge in the U.S. Open final.

However, by '79, Borg had Connors completely figured out. From the base line, Borg was slightly steadier, and, by now, his serve was light years better. Plus, Connors would never try a change of strategy to finesse. He just kept pounding from the back court and getting thumped in the end.

Now, surprising as it seems for a player of Connors' historical stature, the Belleville battler has lost to Borg nine consecutive times over three years.

Once form has been established in tennis, as Borg's mastery of Connors has been demonstrated, it takes a dramatic factor to change it. A "good day" or a bit of luck just won't do it, though tennis promoters keep swearing that's enough.

The only way Connors can beat Borg Thursday is with a dramatic shift of tactics. The old Jimbo may be able to lose gallantly, but only a new Jimmy could actually get over the hump and win.

Surprisingly, Arthur Ashe, captain of the U.S. Davis Cup team of which Connors is a member, is trying to do just that. Ashe has worked with, or talked to, Connors every day here about strategy, particularly.

After all, it was Ashe who, in '75, unveiled a complex and novel soft-ball strategy for playing Connors and stole a Wimbledon triumph with his brain work.

"One of the most important factors in my beating Jimmy in '75 was that some of my advisers convinced me that if I kept playing him the way I had been, I'd just lose again," said Ashe. "The same thing may be true now with Jimmy against Borg.

"Connors has excellent passing shots and lobs, and he can drop shot, too. But he never uses those weapons because he never deliberately draws Borg to the net with balls that are short or are change-of-paces.

"You have to wonder if Jimmy can change a character trait as ingrained as his will to attack constantly."

In tennis, style of play is often a deep-seated reflection of personality and temperament. To change is, in a way, to deny something fundamental in yourself.

That, perhaps, is why, year after year, the same pairs of players produce matches that echo each other so strongly and produce such similar results.

And that is why, unless a daringly less aggressive Jimmy Connors marchers onto Centre Court Thursday, the men's semifinals at this Wimbledon will resemble so much that has gone before them here.

They may be artistic performances, but they will also be foregone conclusions