They are the Bad News Bears now to Hollywood Joe Namath, who lost a few spangles on Monday night; the Good News Bears to Chicagoans, despite losses to New Orleans and St. Louis.

They have a quarterback, Bob Avellini, who has brought the brashness of a New York street kid to the leadership role and he has a defense to match, rowdies to warm the blood of an owner who used to play hard ball as a performer and coach, George Halas.

The superstar is a unique fellow in public life, Walter Payton. He believes in the perfectibility of a running back, a self-flagellant when he does not gain at least 30 yards on every play as he thinks he should.

In a youth culture in which the code word is "cool," Payton is so sensitive about his posture that it affects his well-being, if not his performance.

He has cried because he has failed, as when he was injured in the last game in 1976 and O.J. Simpson beat him out for the National Football League rushing title.

The native of Columbus, Miss., (Pop. 7,500) was so nervous at the prospect of competition in the big city that he missed a week of training camp in 1976.

Some people erroneously associate hyperventialation with advancing age. Its effect has been described in lay terms as like being restrained with a giant's hand on your shoulder as your heart despairingly pumps to propel you up a steep grade.

The medical dictionary says hyperventilation is a state in which there is an increased amount of air entering the pulmonary area from where the blood earries oxygen to the brain.

Payton hyperventilated in games against Minnesota and Seattle in his eagerness to be an overachiever and in his anxiety about possibly failing.

There were two episodes in Monday night's emotional upset of the Los Angeles Rams that apparently bruished Payton's psyche and prompted him to beg off from interviews, although by then it was Tuesday a.m., and he has set aside Tuesdays for comunications with the media.

He fumbled in the first quarter, linebacker Isiah Robertson of the Rams recovered, and Los Angeles went on to score a touchdown for a 13-0 lead.

After the game, Robertson said in his rage about the Bears allegedly taking "cheap shots" at Joe Namath that "the same thing foes for Walter Payton. He clipped (free safety) Bill Simpson on one play. There was no excuse for it. If I ever get a chance I'm going to end his career."

Payton declined to talk in the dressing room, although he led all runners with 126 yards in 24 carries and his 51-yard run in the fourth quarter set up the touchdown pass that won the game.

Payton did appear to indulge in an outward display of his feelins on his first carry of the game, when he gained nine yards. Then his face mask was yanked and a penally was called against the Rams.

The running back got up from between Simpson and Monte Jackson and tauntingly shoved the ball toward them. Then he seemed to be exercishing a kind of kill-them-with-kindness revenge after the penalty was signaled by reaching down and helping Simpson get up.

Dr. Theodore A. Fox, who has been sharing the Bears' problem for 30 years as their orthopedic surgeon, was solicited for an explanation of Payton's nervousness and hyperventilation.

"It was like stagefright at first," he said, "coming from a small school (Jackson State) and a small town and being thrust into the limelight in a big city like Chicago. You would be scared too.

"All I'm saying is that Walter is a human being; not a machine. What he did was natural when he first hyperventilated. He was nervous, fatigued, hot, and a little scared. He is a sensitive person to what is written about hime too.

"He is a superb physical specimen (at 5-foot-10 1/2 and 204 pounds, most of his bulk in his upper torso). He is beautifully built and has powerful muscles. You can be strong and not powerful. Power is strength times speed.

"He has muscles that work past and produce power. He is one of the athletes who have it."

Is it unusual in most athletes?

"It is only unusual becase he got lots of it (power). The super ones have it. It is like with money. There are lots of millionaires. The difference is some have more money than others. Walter is a multi-milti-millionaire in power.