The National Football League, once depicted as the National Football Lottery, is acutely aware of the national football line on each week's games.

"Our whole idea is that the game is not created as a betting vehicle," said Don Weiss, the NFL's executive director. "Betting on the games takes place, of course, but without being pollyannish about it. I think our game is still one where people go to watch the competition."

"How about the hundreds, the thousands, the millions of fans who view the professional schedule as more than a spectatorial delight? What about those who see no reason to watch the second game of Sunday's nationally televised and doubleheader or the Monday night games, except as opportunities to improve their fiscal good fortune? Their home team is rarely involved.

"I'm not saying it's not part of it. I'm saying it's not the main part," Weiss replied. "Given legalized betting, you eventually could create a different climate. The worst thing I could imagine would be to revive what happened in the old Madison Square Garden in New York. I remember going there to watch college basketball. I couldn't understand why people were booing a team they purportedly had come to root for. But that's what used to happen because points were at stake.

"I can't think of anything worse than having one of our stadiums filled with losing bettors . . . because the suspicious of wrongdoing is just as devastating a lot of times, or more devastating than wrongdoing itself."

The NFL, expends considerable effort in an attempt to make sure its image is above criticism, even from the gamblers. Officials are graded, from film, after every game they work . . . The league's security force routinely checks any marked or irregular fluctuation is collected by the league office, then disseminated by the national wire services in order to keep the fans-bettors as knowledgeable as possible.

Injury reports are compiled twice each week for each team. They are 95 per cent accurate. On occasion, however, there is a last-minute surprise.

"Each year, I think our reports get better," Weiss said. "Even in the case of Franco Harris, Rocky Bleier and Roy Gerela for the playoff game last season when Pittsburgh played Oakland, it was no one's fault.

"Pittsburgh honestly didn't know. All three were listed as probable or questionable all week. The team doctor felt, up until the day before the game, that they would play. So far as I know, no one - not even the big gamblers - knew they were not going to be able to play."

That is correct. The spread on that game opened with Pittsburgh favored by 4 1/2 or 5 points - and held there.

"Ninety-nine per cent of the time, when we make a mistake in our reports, it's because of a doctor's honest misjudgment," Weiss added. "If we have a week area, it's the Friday - Saturday period when a guy might turn an ankle late in the week in practice. Often that information is reported locally but is not picked up nationally."

One of the reasons for the steady increase in betting on professional football to its multibillion size is that gamblers believe in the basic integrity of the game. The better the NFL policies its product, the more the betting public is going to wager.

Whereas the Kansas City Chiefs' games were taken off the boards for nearly half a season in the late 1960s, a game on which no action will be accepted now is extremely rare. Players are rarely suspects. Not that the bettors don't claim foul occasionally.

Weiss and the NFL appear to be on safe ground in their response to critics who question the sport's integrity. There is a certain irony, however, about a league brochure that addresses itself to "The Game That Made the NFL."

The game that the NFL sees as a landmark happens to be the same one many of the nation's bettors and bookmakers will never forget - for a different reason.The Colts played the Giants in Yankee Stadium for the 1958 championship. The spread opened with the Colts favored 3 1/2 and 4 points and eventually went up to 5.

Baltimore, after having tied the score late in the final quarter, stopped New York on its fist possession in overtime and proceeded to drive deep into the Giant's territory.

On second down from the seven-yard line, John Unitas threw a side-line pass to Jim Mutscheller, a call that appeared to many observers to involve an unnecessary risk when a field goal on fourth down would have gained the NFL title. Mutscheller caught Unitas' pass and carried to the one for the first down. On the next play, fullback Alan Ameche stampeded into the end zone.

The touchdown beat the spread. A field goal would not have. Such is life in the National Football League.