The Redskins' season opener against the Houston Oilers is becoming a "must game" -- not for the teams involved, but for the bookmakers of Washington.

Since they started taking wagers in mid-week, with Houston listed as a 4 1/2-point favorite, bookies have been deluged with so much Oiler money that they wonder if there are any diehard Redskin fans left in existence. One sporting gentleman reported that, of the first $5,000 he had handled on the game, not one cent had been on the Redskins.

This one-sided action already has pushed the point spread up to 5 or 5 1/2 points, and it will probably even go higher by Sunday.

It is customary for hometown fans to support their local teams with their bankrolls, but in the second half of last season, Washington's bettors began deserting the Redskins. They could see the team deteriorating every Sunday and they knew -- probably even better than the Las Vegas oddsmakers -- just how ineffectual the club had become.

The new season has not rekindled Washingtonians' loyalties. "Last week when the Redskins played Cleveland," said Sneaky Pete, a bookmaker, "we really got burned with the game. Everybody took Cleveland. Even the hard-nosed fans aren't betting the team any more. They may still be rooting in their hearts, but they're betting with their heads.

"Still, this Houston game is really extreme. I haven't written a single bet on the Redskins yet."

Most fans were surprised when Las Vegas established the Oilers as a near 4 1/2-point choice in the first place. Houston, after all, looks like one of the powers in the National Football League, while the Redskins are among the weaklings.

But when a football bet seems obvious, when every amateur handicapper likes the same team, such unanimity of opinion usually serves as a warning signal. Stock market analysts have noted a similar phenomenon and codified it in the so-called "odd lot theory." This holds that when small investors are buying in a stampede, the time has come to sell. When small investors are selling heavily, in a state of panic, it is the time to buy.

In other words: the public is always wrong. So when every bartender in town tells you that he is tapping out on the Oilers, that may be as valid a sign as any that the Redskins are a cinch.

In the cases when the masses love a particular game, their opinion and money are frequently offset by what bookmakers call "the talent" -- the true cognoscenti. I know one of them: Mr. S, a professional sports bettor, whose whole life is devoted to the analysis of football and baseball games. I called him yesterday and asked his opinion of the week's NFL schedule.

His play of the week, he said, is the Washington Redskins.

"I'm not that impressed by Houston," Mr. S said. "They're not that great a team when they're playing away from home, and especially when they're playing on natural grass. Their offensive line is patched up. But the big question is Don Pastorini.

"He played only one quarter during the exhibition season, and I don't know how he can be ready. He's not the type of quarterback I'd like to take a chance on. With the exception of last season, he has always been one of the guys you wanted to bet against. I don't think he's going to do much damage with his passing, and as pitiful as the Redskins seem to be, they seem to have pretty good success stacking their defense against the run.I just don't think Houston has shown enough to be anywhere near a 5-point favorite."

Bookmakers can only pray that that analysis is correct.