Lendl, tennis Masters, and who's No. 1?

The Volvo Masters Championship, which might have settled the question of who deserves the No. 1 ranking in men's tennis, has instead left the whole issue more confused than ever.

According to the year-end computer ranking of the Association of Tennis Professionals, John McEnroe held the top spot followed by Jimmy Connors and Ivan Lendl. But Connors, of course, won both Wimbledon and the US Open along with several lesser tournaments in 1982 - the type of year that in some minds makes a player automatically No. 1 regardless of what happens in any other events. And now Lendl, in what he described as ''probably the best back-to-back matches I've ever had,'' had a relatively easy time in defeating both Connors and McEnroe on his way to capturing the season-ending Masters Championship in New York's Madison Square Garden.

So who gets the No. 1 honor? The International Tennis Federation will announce its choice, which is generally accepted as the official one, next week - but obviously there will be plenty of dissenters no matter what it decides.

The Masters, which despite its January dates is considered the final tournament of the previous year, has reached the point where it ranks right up there among the top events in terms of money and prestige. It may not have the glamour that is associated with Wimbledon or the US Open, but it does have the top competitors in the world battling for $400,000 in prize money. And even while it is concluding one season, it is setting the scene for the upcoming one.

The tournament began with the top 12 players on the 1982 Grand Prix circuit competing for the top prize. The field was pared to four semifinalists in predictable fashion, with the top seeded players (Connors, Guillermo Vilas, Lendl, and McEnroe) all advancing.

After eliminating Connors in a 62-minute semifinal match, Lendl continued his recent dominance over McEnroe with an impressive 6-4, 6-4, 6-2 victory in Sunday's final. Lendl has now beaten McEnroe in their last seven official matches, winning 19 of 20 sets.

As an explanation to his domination over McEnroe, he simply says, ''I'm returning his serve better than I was two or three years ago.'' He is also serving at a pace which makes it difficult to even get your racket on the ball.

Lendl came out firing at the start of the match by breaking McEnroe's serve in the opening game. He gained the only break of the second set as well, that one coming in the seventh game. ''If I'm playing well I'm serving well and that's what happened today,'' Ivan said. ''Under pressure, I was able to come up with the big serve.'' The way Lendl was serving, hopes for a comeback attempt by McEnroe seemed almost impossible.

With Lendl's successful bid at defending his 1981 title here at the Masters, he pocketed the $100,000 first prize, which gave him earnings of over $2 million for the 1982 season. The victory was also his 15th of the season, a record first set by Jimmy Connors in 1974 and equaled by Vilas in 1977.

McEnroe reached the finals by defeating Argentina's Vilas in straight sets by identical 6-3 scores. Both Vilas and McEnroe had good years, with Vilas capturing seven Grand Prix titles and McEnroe winning five.

The crowds, of course, were hoping all week for a McEnroe-Connors showdown, and they cheered wildly for the two Americans whenever they even approached the court. The electricity and excitement grew every time either of them made a good shot, or even disputed a call. But in the end, of course, the power and consistency of Lendl's serving game prevented John and Jimmy from turning this tournament into another chapter of their ''Great American Rivalry.''

Connors, who never really seemed to get into his semifinal match against Lendl, had stated earlier in the week that he would cut back on the number of tournaments he would enter this year. After the one-sided loss to Ivan, however, he appeared determined to bounce back. He finds too much pleasure in life at the top not to fight for it once again.

''I still enjoy playing,'' Connors said. ''I don't enjoy the travel as much anymore, but as long as I have a schedule that suits me as far as the travel and being 100 percent ready to play when I'm there, then I'm going to play.''

When the decision comes for him to retire, he says it will not be a lengthy one. ''I've gone into this year pretty prepared to play and to work at it and grind it out like I did at the beginning of '82. I still have a few things left to do in the game (such as winning 100 tournaments) and I have a few years left to do it in, hopefully. One morning I'll wake up and won't want to get out of bed and go out and practice or play, and then that'll be it.''

McEnroe is also looking to '83 as his year to reach the pinnacle of the tennis world again.

From the start, McEnroe viewed this tournament as an important event for him, because, he said, ''If I'm going to get back to the top, obviously Connors and Lendl are the two guys at the moment that I'm going to have to deal with, so I'm looking forward to playing either of them.''

McEnroe, though, saw his 26-match winning streak snapped when he was beaten by the overpowering Lendl. ''I don't think there's any question he outplayed me ,'' said McEnroe after the match. ''I was very disappointed because I thought I was playing better. I'm going to have to work harder, concentrate, and get in shape.''

Throughout this tournamant, it was evident that the rivalries among the top players are becoming stronger and more intense, this even without Bjorn Borg, who has announced his retirement from tournament tennis.

Lendl, meanwhile, looks ready to bear down and perhaps finally gain some of the major titles, such as Wimbledon and US Open, that have so far eluded him.