It has never been a secret that the top tennis pros are paid appearance money by certain tournaments. It was Guillermo Vilas' bad luck that a tournament in Rotterdam confessed it paid him a reported $100,000. With that evidence, the Men's International Professional Tennis Council suspended Vilas from its sanctioned events for a year, including this fall's U.S. Open and the 1984 Wimbledon.

Predictable squalling came from the nursery. Jimmy Connors and John McEnroe threatened to hold their breath and turn blue if the adults kept taking away their toys. Connors: "If I was suspended, it would not do me a lot of harm . . . It would hurt the tournaments." McEnroe: "If the tournament organizers want to spend part of that (advertising) money on paying guarantees to a particular player to ensure that he competes, they should be able to do so . . . "

Now that Wimbledon and the U.S. Open and a hundred other tournaments have given Jimmy Connors a stage on which to build a reputation, he rises up in his greatness to say those institutions need him more than he needs them. Perhaps the sainted one with the two-handed backhand should move away from his mirror and ask someone else if the world would tilt on its axis should Jimbo quit playing tennis.

McEnroe may be able to see over the top rung of his crib, but he can't see where the chaos of tennis leads. Appearance guarantees make sense on several levels, primarily to ensure the laborer a fair share of the money his work produces. A McEnroe or Connors may mean hundreds of thousands of dollars at the box office, but a quarterfinal loss would net them only pocket change.

The tennis pros ask the difference between appearance guarantees and a basketball player's contract that pays Moses Malone $26,829 a game no matter how he plays. If Dave Winfield hits .200, he is paid the same as if he hits .300. Why should it be all right, the tennis people ask, for Malone and Winfield to take guarantees while we can't?

This is the eternal pubescent's plea for special favors. The tennis pro wants independence. He wouldn't want the constraints of a Malone/Winfield contract tying him to an orderly schedule of honest games with no exhibition work to inflate his income. If Moses were to switch from the 76ers to the Celtics to the Lakers (depending on which offered him the best guarantee that week), then the tennis pros' plaints might be justified.

In an advertising budget, appearance money passes as expense vital to the tournament's public acceptance. Without some top star, a tournament is second-class. When only nine of the top 25 money winners entered the Kemper Open golf tournament, the Kemper advertising people knew it would be cost-efficient to pay a Tom Watson $50,000 appearance money (only 3,000 more customers a day at $15 a ticket is $180,000 revenue).

But golf, unlike tennis, knows that appearance money is a cancer that eats up the game.

"If we ever heard of a guarantee, that player would be gone," said Deane Beman, the golf commissioner.

He would be gone for good reasons that have nothing to do with the economics of sport, but everything to do with making sure the customer knows this ain't pro rasslin'. The customer must believe a sport is honest. He must believe the players are trying to win. Pro rasslin' has an audience, just as demolition derbies have an audience, but neither has anything to do with sports. They are sports bastardized.

Once the customer believes a game is fixed or an outcome arranged to increase its drama, once the customer believes an athlete doesn't care if he performs well, once the customer says, "Sure, the guy tanked it because he's got his guarantee and needs to catch a plane to the next guarantee"--once that happens, your game is corrupted.

And that happens, it says here, when appearance money is first paid. Such guaranteed money plants the seed of doubt in the customers' minds: were those players just going through the motions to pick up the appearance money? From appearance money it is a small step, reportedly taken a thousand times, to splitting first- and second-place money between the finalists.

Under even the best of conditions, sports events are entertainments nearly as much as athletic contests. The line dividing entertainment from contest narrows daily, and up-front appearance money chips away at that line. On McEnroe's exhibition circus ("The John McEnroe Tennis Over America Tour"), the star walked into a darkened arena through dramatic fog and spotlights to the music of "Eye of the Tiger."

For as much as $75,000 a night, McEnroe plays exhibition matches. Small wonder, then, that he sees it his right to extract guarantees to show up for tournaments, even though his work in those tournaments gives him the credibility necessary to demand $75,000 a night for exhibitions.

The players insist that guarantees do not decrease incentive to play well. They point out that playing well is the only way to ensure their continuing lucrative income off the court. They also insist that the desire to win is so great that the money becomes secondary.

Let's breathe deeply and accept all that as true.

It makes no difference.

The appearance of a conflict of interest is nearly as important as the fact. And when customers believe a guaranteed fee is paid to a player no matter how he plays, then the customers properly may wonder if they paid legitimate money to see a bastardized game.