WIMBLEDON, ENGLAND, JUNE 24 -- Defending champions Boris Becker and Steffi Graf are moody, Monica Seles is hurt, and everyone is unpredictable. The real favorites at Wimbledon may be the sentimental ones, the thirtyish Ivan Lendl and Martina Navratilova.

When Wimbledon begins Monday at the All England Club, it won't necessarily represent Lendl and Navratilova's last chances to claim the most prestigious title in tennis. But it may be their best. While the younger set wrestled with personal problems or wallowed about indecisively, Lendl and Navratilova have devoted the past year to winning over the next fortnight.

"A couple of ex-Czechs," Navratilova said. They are as imposingly fit as ever. They are newly popular, perhaps because they are better understood in their comparative old age. They also are clinging to greatness and acknowledge Wimbledon as their last ambitions. Lendl, the top men's seed, and Navratilova, second in the women's draw behind Graf, possess the conviction that victories here would give them proper places in history.

Lendl, 30, winner of eight Grand Slam titles, is seeking his first Wimbledon crown, the one major championship that has eluded him. It is an achievement he perhaps deserves after five years of tireless work as the virtually unimpeachable No. 1 player. He sacrificed much of this season to practice on the grass courts that always have mystified him, and is perhaps more of a genuine top seed than ever before with a recent straight-set victory over Becker at Queen's Club.

"It doesn't matter if I'm a favorite or a 50 to 1 underdog," Lendl said. "I just want to do my best and win."

Navratilova, 33, desires a ninth title that would surpass the record she shares with Helen Wills Moody. Navratilova, like Lendl, has concentrated almost exclusively on the lawns of Wimbledon that she affectionately calls "My grass." She has 17 Grand Slam singles titles and Wimbledon would be a fitting last touch to her career, a feat of competitive heart after years of victories on pure physical talent.

"I feel I have it in me," said Navratilova, bothered by an inflamed left knee. "I want to make sure I leave no stone unturned. I know time is running out, I don't have 15 years ahead of me, but it's not my last year either. I feel very comfortable, because I know I've done absolutely everything I can."

Both players have put in a slavish amount of time readying for the tournament, skipping the French Open to train on grass. Lendl has been sequestered in England for over a month; Navratilova found a grass court on Hilton Head Island, S.C., where she holed up for three weeks with coaches Craig Kardon and Billie Jean King, practicing five hours a day.

Meanwhile, the rest of the field is a puzzle. There were various other methods of preparation for Wimbledon: Some of the players went into hiding and some of them went dancing, and there was the usual pre-Wimbledon blowout at the Hard Rock Cafe. Nothing seemed certain with the stream of upsets leading into the tournament, most notably those suffered by Graf and Becker in recent weeks. It could safely be called as wide-open a Wimbledon as there has been in some time.

If Lendl is to win he must get through a draw that, if form holds, would match him against third-seeded Stefan Edberg in the semifinals and No. 2 Becker in the final. But Edberg and Becker were swept out of the French Open in unprecedented first-round upsets, and then Lendl badly shook Becker, arguably the best grass-court player, by dominating him, 6-2, 6-2, at Queen's Club two weeks ago. Becker and Edberg thus are difficult to predict, off their games and lacking resolve, yet also with the potential to become inspired.

Lendl "just played like a perfect player on grass," Becker said. "One good thing about it: He can't play better, I can."

Lendl's performance suggested that a gamble paid off. After winning the Australian Open in January, he and coach Tony Roche practiced meticulously on grass, right down to finding him the best shoes, his old ones too slippery for the surface. He disappeared from the tour while tennis observers questioned his judgment, predicting he would lack the match toughness needed for two laborious weeks at the All England Club. But he is visibly more confident, in race-horse physical condition, booming his serve and moving much more easily across the court.

"He's 30 years old and he has won three French Opens," Becker said. "And if I was at the same age and hadn't been able to win one particular Grand Slam I would probably do the same thing."

The ultimate arbiter, of course, will be Wimbledon itself. How smooth Lendl's movements have become will be crucial, the fast-paced courts requiring almost instinctive reactions. "It's almost automatic now," he said. That is what Navratilova possesses that he never did. Observers agree the experiment may well have been a wise one, in light of the fact that his old methods certainly weren't working.

"Contrary to a lot of people, I don't feel like this is my last shot," he said. "If I come up bust it would be too bad, but I can't complain about the year I've had."

There are some wild cards for Lendl to consider, such as Henri Leconte, a big-serving obstacle seeded 15th. Also in his way is No. 12 Pete Sampras, an 18-year-old serve-and-volley revelation who could make his presence felt.

The biggest piece of the puzzle is John McEnroe, the fourth seed who has been absent from the circuit for months with nagging injuries and a general lack of interest. He practiced for only an hour a day with an aging Vitas Gerulaitis. Yet he surfaced at Queen's Club to make the semifinals. And then lost to Lendl, decisively.

"He gets an A-plus for preparation," McEnroe said. "I get a D."

McEnroe's strokes of brilliance are fewer and farther between, and he does not seem to have the fortitude for two weeks of Wimbledon play. He also has a difficult draw, scheduled to meet Becker in the semifinals, and that's if he can get past first-round opponent Derrick Rostagno, a dangerous player who held two match points against Becker at last year's U.S. Open. But anything is still possible for McEnroe on a given day.

"He can practice and play badly, or he can not practice and play great," Becker said. "What can you say? He's a genius."

Among the women, there simply is no telling what can happen, chiefly because the once invulnerable Graf has fallen from her pedestal so resoundingly. Graf was confused by her upset loss to Seles in the French final. "I'm lacking confidence, something is missing," she said.

She also is pressured by allegations that her father, Peter, sired an illegitimate child and paid blackmail money, with which the local tabloids are liable to make her life miserable. Her difficulties are compounded by the fact that both Seles and Jennifer Capriati are in her half of the draw, while Navratilova has an apparently clear path to the final.

Yet third-seeded Seles also is an uncertainty, since she pulled a stomach muscle last week. She required four days of rest that may affect her astonishing recent level of play: The French was her sixth straight tournament victory. She remains somewhat inexperienced on grass. So does Capriati, in her first Wimbledon and seeded 12th. She faces troublesome veteran Helen Kelesi in the first round.

Navratilova's chief opponent is time, which confronts her every day. Her knee is a question mark, the inflammation comes and goes and is caused by floating cartilage that requires arthroscopic surgery. "It's an old knee, it's beat up," she said. She holds herself together with ice, aspirin and tape. She is traveling with an osteopath and a masseuse.

"Yesterday I felt 50, today I felt 15," she said. "It's a day to day thing."

TODAY'S FEATURED MATCHES

Centre Court

Boris Becker (2), West Germany, vs. Luis Herrera, Mexico; Henri Leconte (15), France, vs. Simon Youl, Australia.

Court 1

Ivan Lendl (1), Greenwich, Conn., vs. Christian Miniussi, Argentina; Michael Chang (13), Placentia, Calif., vs. Jose-Francisco Altur, Spain.

Court 2

Yannick Noah (16), France, vs. Wayne Ferreira, South Africa; Guy Forget (11), France, vs. Lars Wahlgren, Sweden.

Court 13

Brad Gilbert (7), Piedmont, Calif., vs. Bruno Oresar, Yugoslavia; Jim Courier (9), Dade City, Fla., vs. Mark Kaplan, Stamford, Conn.