The opening lesson in handicapping the 1979 NFL season offer the three Rs: restraint, reason and revenge.

Restraint always is important, particularly during the first few weeks of play. The risks should be small until the form begins to take shape, until the armchair player has had an opportunity to view as many games as possible on the tube.

Preseason games are meaningless and, quite often, can be deceptive. Does anyone believe, for instance, that the Atlanta defense is as inept as it appeared to be during the four exhibition contests?

The ability to reason is what handicapping any sport is all about. The man with the good opinion will prevail over the course of the year and the years, although covering the spread is a tough game because it is necessary to risk a hypothetical $11 with every selection in an attempt to win $10.

"That's the margin, the vigorish, 11-to-10, and it will wear any player down, in time," contends Bob Martin, the "Head Linesman" for much of the nation who works out of Las Vegas.

Martin is right, more often than not, in the matter of sports and betting. But "Playing Football" will continue stubbornly on its way until encountering a losing season. The record shows an uninterrupted stretch of success since the column began in 1974, with hypothetical earnings of $28,219 accruing from a 175-131 (57 percent) effort.

Not that I win every week. I don't. Nobody does. Which is one difference between the public handicapper and the private tout. The guy in private business cannot afford to admit he ever loses. If, this year, "Playing Football" beats the numbers 10 of 16 weeks during the regular season, it will be excellent.

Which brings us to the first picks and the last of the three Rs, revenge.

Atlanta defeated New Orleans twice in 1978, 20-17 and 20-17. The Falcons wound up 9-7 in the NFC West and in the playoffs while the Saints were 7-9 and watched the postseason action as Atlanta downed Philadelphia and lost to Dallas.

In both meetings last year New Orleans had Atlanta beaten, only to see the victory disappear in the final seconds. The loss in New Orleans was particularly tough to accept, when the Falcons threw a long pass in desperation and were lucky enough to have the ball deflected in the right direction. It was the miracle finish of 1978.

If there is one team the Saints have had on their collective mind the past eight months it is the Falcons. New Orleans will be primed, and Atlanta may have to go without the services of quarterback Steve Bartkowski. The spread is 4 1/2 with the home team, New Orleans, favored. Take the Saints, for a hypothetical $500.

I will also open with Cincinnati getting 4 1/2 at Denver and Pittsburgh giving two at New England Monday night. Both are worth $250.

The defensive front of the Bengals is developing rapidly, while Denver's offensive line remains suspect.

Pittsburgh is the best team in professional football. A superior effort by Steve Grogan could win for the Patriots, but Grogan's passing is inconsistent. He runs better than he throws, and running isn't what NFL quarterbacks are paid to do.

Tampa Bay is now a four-point favorite over Detroit Saturday night in Florida. "The Lions were the choice by three before (Gary) Danielson got hurt," Martin noted. Dan Pastorini is ready to go for Houston, favored by 4 1/2 at Washington. Chicago, on the other hand, is hurting at several important positions and is down to three points at home over Green Bay.

In other games, Miami is favored by five at Buffalo, the New York Jets three over Cleveland, Philadelphia seven over the New York Giants, Dallas 4 1/2 at St. Louis, Kansas City one over Baltimore, Minnesota eight over San Francisco, Los Angeles 4 1/2 over Oakland and Seattle one over San Diego.