One of the better decisions U.S. Football League Commissioner Chet Simmons made this year was a nondecision. Some wondered what the brassy new league would dub its championship. Simmons was perplexed.

"We were thinking about Super Bowl, Too," Simmons mused, "but we finally decided to keep it low-key, the USFL Championship Game."

The inflationary tendency had, for once, been checked. No claims of international or galaxy-wide dominance. Just a league championship.

The telecast of tonight's game between the Philadelphia Stars and Michigan Panthers (8 o'clock EDT, WJLA-TV-7) will also have a subdued air--10 minutes of preliminary chatter and then it's gametime.

Even those who have been cynical about some of the overall play in the new league will have to admit that two evenly matched teams are vying for its first championship. The uniforms may still seem as foreign as Martian suits, but the action on the field may prove as exciting, if not as adept, as anything the NFL has to offer. The oddsmakers, who were often uninformed in the early part of the 18-game regular season, have wisely called this game a "pick-'em."

From the earliest developmental weeks of the league, many officials ventured that George Allen would probably be the best attraction for a championshp game. Only a small miracle in Philadelphia prevented Allen's ascension.

Last week, his Chicago Blitz led the Stars by 21 points early in the fourth quarter. But by the end of regulation, Philadelphia quarterback Chuck Fusina, who had been having an otherwise awful day, threw three touchdown passes to tie it up.

In overtime, Chicago's exhausted defense could do little to halt a drive led by Kelvin Bryant, the league's most valuable player and No. 2 rusher. Philadelphia, the league's most successful team during the regular season with a 15-3 record, won, 44-38, on Bryant's one-yard scoring dive.

The other playoff game, a meeting between the Panthers and the Oakland Invaders in Pontiac, Mich., may not have been as exciting for fans as it was for those with financial stakes in the league, specifically in Michigan. A. Alfred Taubman, the Panthers' owner, reduced the price of tickets and parking and drew a crowd of 60,000 to the Silverdome--the biggest crowd in the league's brief history.

The Panthers' 37-21 win was notable not so much for what happened on the field as for what followed the final gun. Fans, whose loyalties were formed only three months ago when the Panthers began to improve their team with aggressive scouting and signings, tore down the goalposts and swarmed the turf.

Simmons and his associates chose Denver as the site of the championship game because of the cooler weather there and the enormous success the league has enjoyed in the city. Although the Denver Gold was one of the USFL's least exciting teams, it drew more than 40,000 fans to each of its games. Mile High Stadium holds 75,412 and league officials anticipate a crowd of about 40-45,000 for the championship.

Although the oddsmakers may disagree, Philadelphia should be a slight favorite.In their one meeting this season, the Stars defeated the Panthers, 29-20, on June 5.

The Blitz fared well last week mainly because the Stars gave up the ball seven times through fumbles and interceptions. It is unlikely that Philadelphia will match that dubious performance again tonight.

The Stars' defense is the league's best, and if it can limit the Panthers' passing combination of quarterback Bobby Hebert and wide receiver Anthony Carter, their chances are excellent.