New York — The beauty of the United States Open is where it falls on the tennis calendar , which is late enough to marinate things in eight months of tournament results, but not so late that a player can't make a new beginning.
These factors are particularly relevant to three of the principals in the National Tennis Center's current drama, which begins today and concludes Sept. 12. Martina Navratilova wants to stay on track; defending champions John McEnroe (1979-81) and Tracy Austin (1979 and '81) just want to get back on the ones they've ridden to fame and fortune.
Thus far, 1982 has not been McEnroe's or Austin's year, but the Open is their tournament. Conversely, the Open is not Navra-tilova's tournament, but it has been her year.
She has won 64 of 65 matches in 1982 and been unbeatable since March. But she must keep her streak alive for two more weeks if she's to pocket the biggest bonus in tennis history, end her personal frustrations at the Open, and take a giant step toward completing a Grand Slam (victories in the French, US, Wimbledon, and Australian champion-ships, last achieved by Australia's Margaret Court in 1970).
Navratilova has already captured two legs, and a third if you care, as some do, to lump last December's triumph in the Australian Open with her '82 French and Wimbledon crowns. On a purely mercenary level, there's the Playtex Challenge to consider. It pays $1 million to whoever can win the US Indoors, Family Circle Cup, Wimbledon, and US Open in any one year. She's already banked half that at the first three designated stops.
The cash incentives will surely place extra pressure on her, and to make matters worse, the Open has been Navratilova's Rubik's Cube. She may be on her way to solving it, though. Last year, in her eighth Open appearance, she came closer than ever before, reaching the championship match for the first time. The Americanization of Czech-born Martina ended there, however, as the newly naturalized US citizen fell to Austin 1-6, 7-6, 7-6. That was as close as any non-native had come to winning in singles since 1978, when the tournament switched from clay to hard courts.
In weighing Martina's chances, one shouldn't overlook a potentially unsettling development. Her coach, Renee Richards, resigned recently, leaving only Nancy Lieberman, a basketball player turned trainer-cheerleader, in Martina's corner.
Probably of greater concern for the top-seeded female is the presence of Austin and Wimbledon finalist Chris Evert Lloyd in the women's 128-player draw. They love New York, as their Open records attest. Evert Lloyd has won the tournament five times, and is determined not to end the year without a major title, a phenomenon that last occurred in 1973.
Though only 19, Austin has already conducted two successful campaigns at the Flushing Meadow battleground. Last year's was particularly inspired and launched a strong finish to an injury-marred season. Injuries have again curtailed her playing schedule, limiting her to one tournament since Wimbledon, where she lost to Billie Jean King, who is entered here.
McEnroe, too, has been bothered by an injury and was forced to withdraw from last May's French Open. His only 1982 tournament victory to date came over Jimmy Connors in Philadelphia, but that was in January, and Mac has since lost to the resurgent Connors twice, including in a five-set Wimbledon final.
McEnroe may be experiencing an emotional letdown, or perhaps the rigors of being the globe's top player are taking their toll. But the Open is his home tournament (he's from Douglaston, N. Y.), and he'll be fighting tooth and nail to inscribe his name on the US championship scrolls a fourth straight year.
That would leave him two shy of Bill Tilden's record, yet reaffirm his identity as the greatest rock'n'roll guitarist to play center court. When not competing, he jams with strings of another kind, and even has a small vocal part (''Yeah, yeah'') on a new LP.
At the Open, though, he seldom has time to do much more than eat, sleep, and play tennis. For unlike other male stars, McEnroe enters both singles and doubles, and will join partner Peter Fleming in defending the latter title.
In singles, his chief challenger could be Connors, with Ivan Lendl, Guillermo Vilas, and Jose-Luis Clerc perhaps the top foreign threats. Also dangerous is McEnroe's fellow New Yorker, Vitas Gerulaitis, who has played some big matches in major tournaments and reached the finals here in 1979.
Sweden's Bjorn Borg, a finalist the last two years, is out of the picture entirely, though his countryman Mats Wilander (''the next Borg'') is very much in it. Bjorn wasn't interested in qualifying, a requirement for any player not entered in a prescribed number of tour events.
Players in the qualifying rounds, incidentally, will receive prize money in a tennis first. The world's richest tournament has also raised the pay scale for the singles winners from $66,000 to $90,000.
That kind of money always attracts a crowd, even among players who grumble about the jet noise, match scheduling, and assorted other things. And don't forget the fans. They flock here, too, some 20,000 at a time. By the time the 13-day tournament ends, more than 350,000 will have streamed through the turnstiles and paid between $8 and $25 each for the privilege. Tennis is big league, and there's nothing about the US Open that says otherwise.