There is a new order in the National Football League. Stability is out. The unexpected is in. The rules have changed. The downtrodden no longer have to accept an infinite sentence at the bottom of the standings as punishment for ineptness.

Teams can improve faster than they possibly could have imagined even 10 years ago. Cincinnati and San Francisco are symbols of this transition: a year after both had losing records, they are three days from playing in Super Bowl XVI.

Don't tell them or any of the league's other former weaklings that their ascension is a sign of decay throughout the NFL. In their eyes, this NFL is much better than the old model.

"I know some are disturbed because new people are on the scene," said 49er Coach Bill Walsh. "The only way we could possibly return to what we did have would be to give extra draft choices to the traditionally great teams . . . because some of us will be trying to remain on top of the league.

"There are people who blast parity as though it were blasphemous. But it is a culmination of a lot of hard work by individual organizations. For anybody to talk in negative terms about that work is extremely selfish."

Statistics support the league's gradual change over the last five years.

From 1970, the first season after the AFL-NFL merger, until 1976, seven teams--Dallas, Pittsburgh, Miami, Oakland, Minnesota, Washington and Los Angeles--won 40 of the 56 playoff spots. At least one of those teams was in every Super Bowl during that span, while only two teams outside the Big Seven made the championship game.

From 1977, the first year with significant changes in the playing rules, through this season, those seven teams have captured only 20 of 48 playoff slots. In that span, Denver, Philadelphia, Cincinnati and San Francisco will have played in the Super Bowl for the first time. And this year, for the first time since 1970, none of the Big Seven is a participant.

This season there were six teams in the playoffs with records of .500 or below in 1980. In contrast, Oakland, Pittsburgh, Minnesota, Washington and Los Angeles all failed to achieve winning records.

"The league is so even now that with a proper draft and coaching, I see no reason why we can't go from 6-10 this year to the Super Bowl next year," said Don Klosterman, the Rams' general manager. "A player or two can make the difference now in getting better very fast."

Certainly, the NFL's decision before the 1978 season to begin so-called parity scheduling has aided the weaker teams. Under that system, many losing clubs are paired against comparable opponents the next year instead of facing a steady diet of winners. Yet only three teams, the Giants, the Jets and Tampa Bay, have advanced to the playoffs the same season they had what theoretically were the league's easiest schedules.

The rules changes also have helped. Since 1978, defensive backs have not been allowed to make contact with receivers five yards beyond the line of scrimmage. Since 1977, offensive linemen have had greater freedom to use their hands on pass blocking. As a result, teams have less difficulty constructing a passing game.

Tex Schramm, Dallas' general manager and a major force behind the liberalized passing rules, says the draft and better team management are more important explanations.

"The draft is working better now because it is later (April instead of February) and that allows teams to do more homework," he said. "And more teams have better front offices."

George Young, the Giants' general manager, credits an improvement in coaching throughout the league.

"There are larger coaching staffs and the overall instruction being offered is on a higher level on a league-wide basis," Young said. "This is a year-round business now. Everyone is weight lifting, not just a few teams. Everyone is working long hours. The 16-game schedule opens you up more to injuries, and losing one or two key players can really juggle the standings.

"You once looked for behemoths, especially in the line. Those were the guys who got drafted first, the ones that went in the first 12 spots. Now you take the skill positions first. Cornerback has become a favorite. Six cornerbacks have been taken on the first round the last two years."

Walsh says that in the early 1970s, when Miami was the reigning power, "if you tried to send backs through the line to become pass receivers, they never would have made it. Miami would have tackled them or clotheslined them and gotten away with it.

"I don't think three guys on that Miami defense could run a 40 under 5.0. Now every one of the 11 players we use on our nickel defense can run that fast and most can run 4.5. We have 245-pound linemen, not 270. The teams that have fallen behind are the ones that haven't added quickness."

The transition has created a new position for the NFL: nose guard in a 3-4 defense, the alignment used by 18 of the 28 clubs, including both Super Bowl participants. Scouts now look for offensive linemen with long arms who can fend off pass rushers. Teams rely much more on specialty substitution according to down and distance instead of depending on a 22-man nucleus.

"I'll tell you something else, too, that's really striking," Young said. "Remember when there was all that uproar over Paul Brown calling the plays for Otto Graham? I can't think of a team in the league now that doesn't call the plays for its quarterback. There is a lot more thinking being put into what is being done with every team."

San Francisco, especially, stands out as a prime example of the short-order work that now can be done to remake a team into a championship contender.

In three years, Walsh has turned around a 2-14 franchise by honoring today's main building rules: he has drafted well, he has made the 49ers much quicker and he has bolstered their pass rush.

Only nine 49ers are left from pre-Walsh days. Of the 36 new players, two were drafted in 1979, six in 1980 and six in 1981. Nine of those draftees are starters: quarterback Joe Montana, receiver Dwight Clark, running back Earl Cooper, linebackers Craig Puki and Keena Turner, defensive end Jim Stuckey and the three rookie defensive backs, Ron Lott, Carlton Williamson and Eric Wright. Starting even one rookie in the secondary once was considered suicidal.

Walsh also dipped successfully into the free-agent pool. He ran tryouts for more than 100 candidates, and gleaned 15 over the three years, including three starters. Linebacker Jack Reynolds was signed last summer after he was released by Los Angeles; he led the 49ers in tackles this season.

Finally, Walsh, who doubles as general manager, acquired defensive end Fred Dean from San Diego, giving San Francisco a better pass rush. He filled a hole in his offensive line by obtaining tackle Dan Audick from the Chargers. And he got his starting tight end, Charle Young, in a deal with the Rams.

"If you go position by position, San Francisco's personnel doesn't measure up to the best teams," Klosterman said. "But Bill Walsh has done an incredible job. You have to focus on him."

That is the coaching element mentioned by the Giants' Young. The 49ers also have been relatively injury free. They haven't lost any starter for more than a game this season. They also are among the league's quickest teams, they have one of the best pass rushes and they have a superior passing attack. In all, they have the ideal formula for today's game.

Cincinnati has succeeded with more reliance on traditional methods. The Bengals have depended almost totally on the draft. When they had poor records, they refused to trade their high picks. Instead, they swapped players for more choices, and wound up having two first-round picks from 1976 through 1979.

Eight starters on their Super Bowl team are first-round draft picks. Every starter is a draft choice and 24 of their 45 players were taken in the first, second or third rounds. Only 10 players weren't obtained through the draft, and they were signed as free agents. Not one Bengal was acquired by trade.

All their starting defensive linemen were No. 1 selections. Their offensive line contains more high-round choices than any other in the league. And when they decided they needed more speed at wide receiver this season, they used their top two choices to nab David Verser and Cris Collinsworth.

"They were in a situation where they needed only a few players to put them in contention," Young said. "With more speed on the outside, they could throw long passes more effectively. Suddenly, their offense is much more explosive."

Yet, until Cincinnati hired Forrest Gregg to discipline all this talent, the Bengals still floundered. But with Gregg's input, combined with those quick receivers, few major injuries and a well-developed passing attack and pass rush, the Bengals moved from a 6-10 team to a Super Bowl finalist in one season.