The U.S. Football League has endured debate from within, missed payrolls and rumors of demise. With this weekend's games marking the end of the regular season of its last and most troubled spring, the relief can be felt around the league.

Despite the litany of controversy, USFL owners and officials are calling it a successful season. The bitter spring vs. fall debate that lasted for two seasons has been resolved. Quality of play, though it has gone largely unnoticed, has improved. Most importantly, however, "we survived," says Baltimore Stars owner Myles Tanenbaum, whose team closes out its schedule against Tampa Bay at College Park's Byrd Stadium today at 2:30 p.m.

Some of the USFL's difficulties have been resolved. For example, Tampa Bay owner John Bassett has given up his idea of starting a new spring league (although mainly because of poor health resulting from chemotherapy treatments for two brain tumors).

But the instability continues. Tampa Bay and Orlando are seeking a merger, Los Angeles is crying for an owner, San Antonio, which has been late with paychecks, could use some cash flow. Only three teams can claim a rise in attendance; all others are down and the league overall has lost 10 percent of its fans.

"Sometimes it has sounded like 'The Perils of Pauline,' " Commissioner Harry Usher said. "Any time you have financial problems there is going to be some of that. But the problems of the league are greatly exaggerated.

"The competition has been good, each team has succeeded in entertaining people, we've developed and gotten another year under our belt. We've been able to show people we are serious, despite the inordinate number of rumors to the contrary."

It may not matter if the league does not stop the exodus of fans. The Denver Gold, one of the eight teams in the playoffs, is not likely to play at home during the playoffs because of its dreadful attendance figures; despite its 11-6 record, attendance fell 57 percent, the team drawing an average of 14,519 fans.

The Stars, who moved from Philadelphia to College Park last year in anticipation of a fall schedule, are averaging 14,479 fans compared to 28,668 last year in Philadelphia. In the last three home games they have failed to draw 10,000. The Stars probably will not play at home during the playoffs either, but that has more to do with their 9-7-1 record.

The three teams with improved attendance are New Jersey, up 8 percent with the signing of quarterback Doug Flutie; Orlando, formerly the Washington Federals, up 237 percent, and Memphis, a playoff team that is up 10 percent.

Another major obstacle still to be dealt with is television. Ratings have sunk to almost test pattern levels. The league rating on ESPN is 2.0, down from 2.9 last year. The USFL has filed a lawsuit against ABC over whether the league should return $7 million in television money because it left some major markets this year. So far, it is without a network contract for 1986, and depositions in its antitrust lawsuit against the NFL are due to be taken this summer.

One of the top priorities is finalizing plans for the USFL television syndication. Without a network contract, it will have to rely on an ESPN contract and agreements with local stations for revenue and exposure, which even Usher admits is a shaky proposition. The idea, once again, is survival.

"I don't think in today's marketplace anything is equal to a network agreement," he said. "But the syndication route is a viable alternative, and under the proper set of circumstances it might produce some good returns. By the time we start playing 15 to 17 months from now, hopefully there will be an awareness that we aren't going to just fold up our tents."

The upcoming playoffs could give the league something to be remembered for before it goes into that long hiatus. At least some competitive flourish couldn't hurt.

"Realistically, the memories will fade too darn fast; people won't remember if they're exciting or not," Tanenbaum says. "The significance of the playoffs is in the playoffs themselves, the competition. It doesn't matter if it's spring or fall. We'd love to do it as a Baltimore team, as a parting shot."

The eight playoff teams already have been decided, which leaves only the home field advantages to be determined. Since the league also is factoring in attendance figures, the Stars don't seem in good shape, and Coach Jim Mora says, "The more I hear from the people upstairs, our chances of being a home team are very slim."

The Stars' attendance has fallen off 49 percent from last year, and there were as many as 10,000 no shows at one game, but they are the only team to make it to the playoffs all three seasons.

Oakland has clinched the Western Conference championship with a 12-4-1 record and meets Houston Monday in the Astrodome. New Jersey and Birmingham will decide the Eastern title today at the Meadowlands.

These could be some teams' last games. Usher has said before that he would like to pare down from 14 teams to 12, for more financial security and greater unity. Two or three franchise moves also are predicted, to avoid stadium conflicts and direct competition with NFL teams with the shift to fall. The Denver Gold and Houston Outlaws probably could not afford to compete directly with NFL teams and might be seeking new sites. The major markets seem secure, however, which is good news for the Los Angeles Express, the ownerless team under league supervision.

"The scenario is, New York, Chicago and Los Angeles, with nine other cities where the NFL isn't," Tanenbaum said.