John McEnroe and Martina Navratilova have spent most of the year on another tennis planet. Recently, however, the two were brought to earth, a reminder that neither top-seeded player is assured of victory in the US Open Championships, which begin their Aug. 28-Sept. 9 run in New York today.
In tuning up for the Open, McEnroe lost to Vijay Amritraj last week. Navratilova, meanwhile, barely survived a scare in New Jersey by beating doubles partner Pam Shriver 6-4, 4-6, 7-5 in the singles final.
McEnroe's only other loss this year occurred at the French Open in June, when Ivan Lendl erased a two-set deficit to win his first Grand Slam event. Navratilova, whose last loss was to Hana Mandlikova in January, kept her six-month winning streak alive, but saw the sheen of near-invincibility dulled.
The match with Shriver marked only the 13th time Martina has been extended to three sets since January 1983.
All this is not to say that the game's top-ranked players won't etch their names on the Open trophies. They are, after all, supertalents at the height of their careers.
Winning the US Open is never easy, though, not with everybody who is anybody in tennis trying to become a bigger somebody. Injuries, however, will prevent Tracy Austin, Andrea Jaeger, and Yannick Noah from taking part and Billie Jean King is only playing doubles.
Still, full fields of 128 men and women come seeking fame, fortune, and a higher ranking on the 16 acres of hardcourts at the National Tennis Center in Flushing Meadow, home to the sport's richest tournament.
Until last year, Navratilova was a prime example of just how hard it is to win this cacophonous event, made literally so by jets from nearby LaGuardia Airport and huge crowds that break records each summer.
For a decade the US Open title eluded Navratilova. Then, finally, the Americanization of naturalized citizen Martina was completed last September, when she crushed six-time champion Chris Evert Lloyd 6-1, 6-3.
To Evert Lloyd's credit, she has not given in to the discouragement that could beset her after 12 straight losses to the world's No. 1 player. ''If it weren't for Martina, I'd be dominating women's tennis,'' she says.
As it is, Chris has regularly reached the finals of major events, only to have Navratilova underline the current talent gap between herself and the best of the rest. She has already recorded convincing victories over Evert Lloyd at this year's French Open and Wimbledon tournaments.
Evert Lloyd can't be taken lightly, though. She owns a 72-7 lifetime record in Open play, has seriously worked at improving her net game, and is generally better able to concentrate on tennis now that she and husband John Lloyd have ended their separation. She also is coming off a victory in the Players Challenge tournament in Montreal.
If Evert Lloyd doesn't reach the US Open final, third-seeded Hana Mandlikova might. She and Evert Lloyd are in the same half of the draw, but Chris has frequently had Hana's number. Chris beat her in the 1980 and '82 US finals and this summer's Wimbledon semis. Navratilova's biggest stumbling block could be fourth-seeded Shriver, who can use her long reach and over-size racket to wreak havoc on the Open's fast courts. Shriver has been a spoiler before, having ended Martina's bid for the US crown in 1978 and 1982. The transplanted Czech is no longer wilted lettuce under pressure, however, a fact she's made plain by winning the Grand Slam - successive victories in the French, US, and Australian Opens, plus Wimbledon.
Like Martina, McEnroe doesn't need anyone to reiterate the perils of playing in the Meadow. After winning three straight Open crowns begining in 1979, John has been derailed before the finals the last two years. Ivan Lendl dethroned him in the semifinals in 1982, and Bill Scanlon upset him in the '83 quarterfinals.
McEnroe is at the peak of his powers, though, and gradually seems to have brought his temper under control. At Wimbledon he was downright mannerly compared to previous years, and as Jimmy Connors can attest, McEnroe's tennis was almost flawless. John buried Connors 6-1, 6-1, 6-2 in the most lopsided Wimbledon final in 46 years.
That embarrassment undoubtedly has weighed heavily on Jimmy's mind, for he is a fiercely proud player. He probably will use the loss to stoke the emotional fires in New York, where he always seems to play with extra intensity anyhow.
In fact, he has won five US Opens, including the last two, both against Lendl. McEnroe may have been born in New York, but Jimmy acts like it's his turf. Together the two Americans have monopolized this tournament, accounting for every men's title since the Open moved from Forest Hills in 1978.
Trying to break up this southpaw domination will be the second-seeded Lendl, whose booming right-handed serves and groundstrokes are among the sport's most feared shots. Lendl appeared to have a mental block in the big tournaments, but with his victory over McEnroe in Paris he has cleaned the slate of lingering self doubts. The chief competition in Lendl's side of the draw may come from No. 4 Mats Wilander.
Among dark horses lying in wait in the men's draw are Wimbledon semifinalist Pat Cash of Australia, and Americans Eliot Teltscher, Jimmy Arias, and Aaron Krickstein. The top women must beware of Bulgarian teen-ager Manuela Maleeva and Britian's Jo Durie.