After a year of abstinence and self-control, I am falling off the wagon tonight.

In the middle of last fall, I swore off betting football. I made this decision after Tampa Bay covered the point spread against Houston on an 86-yard run with a recovered fumble. It was the umpteenth time that season that an improbable, fluke play had enabled the wrong team to win, and I couldn't take the aggravation anymore. I resolved to spend future Sundays lingering over brunch, romancing blonds and taking nature walks.

While my life did not become quite that civilized, I did quit betting except for an occasional recreational wager. My mental health improved considerably. While my friends were suffering the usual weekly agony (watching Green Bay blow a 17-0 lead in the fourth quarter against Atlanta, for example) I have enjoyed a tranquil fall.

But that tranquility must end this evening, because even a prudent man does not pass up the opportunity to win easy money. That is what my principal consultant on gridiron matters assures me is being offered in the nationally televised game between the Los Angeles Rams and the Chicago Bears (WJLA-TV-9 at 9 p.m.).

I have written about Harry periodically in this column. He is a professional sports bettor, a man who makes his livelihood strictly by his wits, who spends every day ruminating over statistics and matchups. Because he is a professional, one who knows all the pitfalls of the games he plays, Harry rarely utters such phrases as "mortal lock" or "can't lose."

So I was shocked to hear him talking in such terms as he discussed the Rams' superiority over the Bears.

Superficially, the game looks evenly matched. Both teams have 1-2 records. The point spread is even.

"I know Los Angeles has looked pathetic, and I don't care much for (quarterback) Pat Haden," Harry said at the outset, anticipating my thoughts, "but they have talent far superior to the Bears."

The Bears looked bad losing to Green Bay and San Francisco in their first two games this season, but beat Tampa Bay last week, 28-17. "I had a chance to see that game," Harry said, "and it was hard to believe that the Bears won. Tampa Bay looked much better in losing. Chicago is the most inept team I've seen.

"On defense, their cornerback, (Terry) Schmidt, No. 44, is so slow that I could beat him on a pattern." (And Harry isn't so sprightly). "The rest of their secondary is weak. Their linebackers are weak. All they've got are three defensive lineman who are okay; it looks like Alan Page has finally had it. Tampa Bay can't run on anybody and they ran on the Bears."

On offense, Harry said, the Bears have many glaring weaknesses, too: "When they lost their best wide receiver, James Scott, to Canada, they were left with a bunch of receivers with no speed at all. And they've got a place-kicker they cut three times before. Against Tampa Bay his extra points were barely making it through."

While the Rams may be beset with problems, they did play creditably in defeat against Houston, and they whipped the Packer team that beat Chicago. "I look for the Rams to win by at least 14 points," Harry said. That's enough to make me cancel my usual Monday-evening nature walk.