The biggest edge bettors have in attempting to cover the point spread on NFL games is the knowledge they build about their home team as the season unfolds.

"We have good sources of information in all cities," a prominent Las Vegas linemaker assured, "but it's not the same as being there, being able to see things first hand. We don't see every team every week. So there's no way we can have the insight about a particular team that a bettor who follows that team, week in and week out on television, can develop."

That makes sense, although many professional gamblers feel betting on the pros is nothing more than a numbers game. They don't care if they ever see a game. Ultimately, whatever happens on the field will be reflected by the final scores and the numbers they live by will be adjusted.

I have always believed that gambling against the spread is much more of an exercise in observing line play than in juggling numbers. Admittedly, no two people see a game the same way. And handicappers differ sharply in their emphasis of what is important, but the forming of opinions for betting purposes should be based on what you saw, not what you read, heard, felt or put into the computer.

Professionals who regularly exchange tapes of recent games involving teams they want to see have a built-in advantage. For example, the Raiders, Washington, Dallas and Miami frequently are made available to everybody by the nation's television networks, but Denver, although 5-1, has been seen by comparatively few outside the Rocky Mountain region.

Again, the average fan's advantage is being able to see one team, his home team, 16 times a season. The tendency, unfortunately, is for too many fans to support blindly the home team. The trick is to be able to look at the home team as a commodity. Otherwise, the advantage becomes a disadvantage.

The Vegas line this week lists Seattle 11 over Buffalo, St. Louis 3 over Chicago, New England 7 1/2 over Cincinnati, Philadelphia 6 over Indianapolis, Washington 5 over Dallas, Miami 17 over Houston, New Orleans 3 over the Los Angeles Rams, the Los Angeles Raiders 10 over Minnesota, Atlanta 4 over the New York Giants, Cleveland 1 over the New York Jets, San Francisco 8 over Pittsburgh, San Diego 2 1/2 at Kansas City, Detroit 4 over Tampa Bay and (Monday night) Denver 6 1/2 over Green Bay.

All the favorites are playing at home, except the Chargers.

I'll go with Washington and St. Louis for an imaginary $500 each and take $250 apiece on New England, Miami, and Denver.

The Redskins are banged up quite a bit, but I have a hunch quite a few of the walking wounded will get healthy for the Cowboys, at least for spot duty. Tony Hill's return should help Dallas' passing game. Tom Landry's main problem continues to be that his offensive line doesn't give Tony Dorsett breathing room. Washington can control both lines of scrimmage. Give the 5.

The Cardinals' offense is impressive, nicely balanced, featuring the running of O.J. Anderson and Stump Mitchell and the receiving of Roy Green. St. Louis is still hurting on the corners. If Dallas, surprisingly, couldn't exploit that weakness, the Bears don't figure to, either. Give the 3.

A few weeks ago I wrote that young New England quarterback Tony Eason had a lot to learn. He's learning. The Patriots have the perfect patsy with which to go 5-2 in hosting Cincinnati. Boomer Esiason, the Bengals' rookie quarterback from the University of Maryland, managed to put all of 13 points on the board against Houston's hopeless defense. This week he'll discover what playing in the NFL is really like. Give the 7 1/2.

Giving 17 points is ridiculous, unless it's Miami playing at home against Houston. This might be the mismatch of the year. The Dolphins should score 40. The Oilers can't score 21 against Miami. Pardon the expression, but give the 17. (one note: if Hurricane Josephine appears ready to make playing conditions difficult, scratch this selection.)

Denver's defense is doing the job once again and the offense gradually is coming along. I loved Forrest Gregg's statement, after the Packers lost to San Diego Sunday to go 1-5. "We're over the hump," Gregg said. Maybe so. Then again maybe he can't see the trees for the forest. The Broncos will be sky-high for this one on national TV. Give the 6 1/2.