To most fans, pro football looks the same as ever: Games are still won by blocking and tackling, coaches are still uttering the same cliches, Howard Cosell is babbling the usual drivel.

To people who bet on it, however, the sport seems to be undergoing a subtle but important change. Emotion and motivation have become dominant factors, rather than the interplay of the teams' strengths and weaknesses. The National Football League is getting to be a bit like the National Basketball Association, where the winning team is usually the one which feels more like playing on a given night.

The most obvious manifestation of this change is the growing importance of the home field. Of course, the home-field advantage has always existed, but it has become so dominant this year and last that bettors believe they can win by betting home-team underdogs blindly.

Las Vegas keeps adjusting its point spread to diminish enthusiasm for the home team. Last week it even made a 1-7 club the 2 1/2-point favorite over a 6-2 team. But even as Vegas tries to compensate, the home-field advantage keeps getting stronger and stronger. That 1-7 team, Cincinnati, beat Philadelphia in a runaway.

This season, home-team underdogs have covered the spread 70 percent of the time. The overall record of home teams, without regard to the point spread, is 73-53.

But even these statistics do not begin to convey the way the home team's motivation overrides every other handicapping factor. When the Eagles played the Redskins here, anyone who had watched them play two weeks earlier knew that Philadelphia was the superior team. The Eagles had won in the most basic of ways, dominating the line of scrimmage, ripping open big holes for Wilbert Montgomery.

Yet the oddsmakers and bettors of America knew that this was almost irrelevant. They established the Redskins as a three-point favorite in the rematch, figuring that the encouragement of the home crowd would help make up for everything else. The bettors were right.

Bettors know that even games which are total mismatches on paper can be made close by the home-field factor. An encounter between the powerful New England Patriots and the slumping, injury-ridden Buffalo Bills ought to be a runaway. Yet, because the game is being played in Buffalo, the Patriots are a mere 4 1/2-point favorite. Even at that price, they are probably a sucker bet.

What has happened? The nature of home fields and home crowds hasn't changed. But in the NHL, as in the NBA, teams often have so little incentive to win a regular-season game that the encouragement of the home crowd makes the difference.

With the 16-game schedule and the expanded playoff format, teams can afford to relax a few times during the course of the season and still make the playoffs without worry. Even marginal teams like the Eagles and the Redskins seem virtually assured of playoff berths. If an NFL team does relax for a week, it is likely to be beaten, because there is such a parity of talent around the league.

To NFL Commissioner Pete Rozelle, this may be the fulfillment of a dream, the realization of the claim that "on any given Sunday. . . ." But as a bettor, I find the changes in pro football repugnant.

Handicapping football is a tough intellectual challenge. Except for horse racing, no form of gambling demands such great analytical ability and keen power of observation.

Over the years I have listened with awe as my colleague Gerry Strine would explain matchups to me, would tell me that Oakland was going to beat Minnesota because Gene Upshaw and Art Shell were going to manhandle Jim Marshall and Alan Page on the line of scrimmage.

That kind of analysis was exciting to make and satisfying to see fulfilled, but not it has become largely irrelevant (at least until the playoffs). Even Strine, the great proponent of handicapping according to offensive and defensive matchups, is concentrating his play on home teams and teams that figure to be emotionally high.

Pro football may be just as beatable a gambling game as it has always been. But I'd rather beat it with intelligent analysis, rather than a vague hope that the Buffalo Bills are going to be "up" before the home crowd this week. You might as well shoot craps. Or bet professional basketball.