The executives who run the three major networks and that sly new member of the broadcast fraternity, Br'er Fox, have resorted to a number of clever tactics this season in an effort to steal viewers away from cable, VCRs and each other.

First, they began the season early. Indeed, the old one hardly ever ended. A number of new series have been shown already this summer, many of them twice, in an effort to grab the attention of anyone who didn't flee to the beach.

They also managed to generate controversy before a single program had been aired by previewing to the television press several shows with questionable dialog and situations. Networks, some critics have charged, are mimicking the low level of taste of Fox's "Married ... With Children," a hit show everybody criticizes after they stop laughing at it.

But if there is concern about breaches in the taste barrier, there has also been a certain back-to-basics movement in the industry. A number of proven production houses with long records of success have been signed up to generate series this season.

Such proven showsmiths as Steven Bochco ("Hill Street Blues," "L.A. Law"), Thomas L. Miller and Robert L. Boyett ("Perfect Strangers"), Linda Bloodworth-Thomason ("Designing Women") Gary David Goldberg ("Family Ties," "Open House") have been enlisted to pound out one show after another.

The products of these liaisons have run the gamut from Bochco's highly innovative "Cop Rock," a mating of the musical and the dramatic for ABC, to sitcoms that are, by comparison, strictly conventional.

The most interesting of those sitcoms have been built upon the talent of relatively unknown personalities. Foremost among them: Rap artist Will Smith of NBC's "Fresh Prince of Bel Air" and standup comic Lenny Clarke of CBS's "Lenny."

But the most dramatic development of the season involves two returning shows rather than any new one. In a bold move, Fox Broadcasting Company has moved its biggest hit, "The Simpsons," to Thursday night, opposite NBC's ratings titan, "The Cosby Show." What will happen when the irreverent Bart and the gang leave their cushy Sunday night timeslot and run up against all those cute Cosby kids?

"There's a lot of risk-taking, which is what this network is all about," said Peter Chernin, president of the Fox Entertainment Group. The move is an attempt to establish Fox on what is for them a new night of programming. Fox reasoning holds that no one else has positioned strong shows opposite the NBC Thursday juggernaut, which can't plow on forever. If and when "Cosby" loses steam, Fox intends to be there.

"It's a season aimed at long-term growth," said Chernin. "My feeling was that we should not rest on what we accomplished last year. We're making some ballsy moves. Thursday is a great night for us. Other shows are getting older. We're not taking aim at 'Cosby.' Our move is aimed at growing the network."

With both series having aired only reruns, estimates of how the matchup would turn out were cautious, with no one claiming victory or conceding defeat.

"I think it's tough to predict off repeats in the summer," said Warren Littlefield, president, NBC Entertainment. "But the one thing that seems to have happened is that more people came to the sets. 'Cosby' wasn't hurt, 'The Simpsons' did okay, but more people went into the time period. And that's good for television."