Perhaps the time has come to get a card with Ditch Diggers of America. For the third straight season I've dug a hole for myself, Playing Football.

This is not my season. Comebacks may be thrilling on the football field, but in terms of investing against the point spread, a much better approach is to build a big early lead and coast home. That, I've rarely achieved, in seven successful seasons against the spread.

Ah, but this is the eighth year, and there are no guarantees that next weekend will turn out any better than last weekend. Only the belief that, soon now, several of the slightly superior squads in the National Football League will begin to play up to their potential consistently.

We have seen flashes of excellence from four or five teams: Philadelphia, Dallas, San Francisco, Cincinnati, and, maybe, Denver. For the most part, the gap between the best and the worst of the 28 teams has been unbelievably small. You could throw a blanket over the entire bunch on some Sundays. Only one team has consistently stood apart: Baltimore, with its ineptness on defense.

The NFL season suddenly begins to turn very serious, however, around Thanksgiving Day. Fun and games are over. For the pros, it's no longer simply football, it's money-ball. Over the years, that's the biggest edge I've had in handicapping the league. I'm much more comfortable risking my imaginary money when the teams are playing for big money.

So here I go, one week at a time, one game at a time, employing the same sensible money management that has resulted in past success.

Detroit attracts $750 today as a 2 1/2 point favorite at home against Kansas City. The Lions should make the playoffs. They have played everybody tough and the victory two weeks ago over Dallas had to be a big boost to their confidence. The Chiefs are more solid in the secondary, but I doubt they have the ingredients necessary to exploit the Lions' weakness against the pass.

San Diego draws $500 favored by 3 1/2 at home against Denver. The Chargers still have the best offense, with Dan Fouts throwing. If the defense will only start tackling a little like professionals, San Diego will get to the playoffs. The name of the game in the '80s is scoring, and no one scores quite like the Chargers.

Cincinnati gets $500 favored by 2 at Cleveland. The Bengals are on a tear this month, developing into a team of Super Bowl quality. The Browns beat them early, 20-17. Since then Cincinnati has improved steadily while Cleveland has found reaching the .500 mark to be difficult.

Miami is a $1,000 pick at home Monday night against Philadelphia, as a two-point underdog. The game opened at one. The Eagles rarely lose two in a row under Dick Vermeil. Then again, when has Don Shula lost three straight? Vermeil's innate conservatism should play into Shula's hands in this match up that features two outstanding coaches.

I'll also dabble $250 each on Dallas and Pittsburgh. The Cowboys, favored by 12 1/2 today at home against Chicago, are going to put everything together soon and blow out the opposition. The Bears are a likely candidate.

Pittsburgh, the past two weeks, has shown signs of rallying for One Last Stand. I'm prejudiced. The Steelers have always been my favorite organization. Sentiment alone dictates going along for the ride in Three Rivers Stadium giving 6 1/2 to Los Angeles.

In other games this week, Las Vegas lists Atlanta three over Houston, the New York Jets 12 over Baltimore, Minnesota seven over Green Bay, San Francisco five over the New York Giants, Oakland at Seattle even, New England four over St. Louis, Tampa Bay one at New Orleans and Buffalo five over Washington.

Last Week-$2,500

Season Totals-$4,375

Last week's results: Cincinnati, giving 3 1/2, defeated Denver, 38-21, plus $250; New York Jets, giving three, defeated Miami, 16-15, minus $825; Oakland, giving 2 1/2, lost to San Diego, 55-21, minus $825; Los Angeles, giving 2 1/2, lost to San Francisco, 33-31, minus $825; Atlanta, giving four, defeated Minnesota, 31-30, minus $275. Won-lost record: 25-28