'Bay City' is about baseball - or, rather, the people who play it

Warning to nonbaseball fans: Just when you thought it was safe to turn on TV without having to cope with regular-season games, the playoffs, or the World Series, NBC is premiering a new baseball-oriented series.

Bay City Blues (NBC, Tuesdays, 10-11 p.m., premiering tonight)m just about completes the new TV season schedule, a monumentally unsuccessful one for all networks, but especially for NBC, which has not managed to win large audiences with any of its nine new shows. All languish in the lower depths of the Nielsen ratings. As a matter of fact, only two new network shows made the top 20 last week, both on CBS: ''AfterMASH'' and ''Scarecrow and Mrs. King.'' Another seeming winner, ABC's ''Hotel,'' was knocked off the air last week by ABC's World Series broadcasts.

Late-entry ''Bay City Blues'' was created by the executive producer and co-producer of ''Hill Street Blues,'' Steven Bochco and Jeffrey Lewis. The similarity in titles derives mainly from the similarity in producers, who probably hope that some ''Hill Street'' viewers will carry over to ''Bay City.'' ''Hill Street'' is, of course, about a police station, and the ''Blues'' is probably a double-entendre, referring to both the color of the uniform and the state of mind of most of the characters. The Blues in Bay City, Calif., however, are a minor-league baseball team, the Bay City Bluebirds.

The two shows share some characteristics: swift intercutting from one story line to another; some very funny moments, as well as poignant ones; speedier-than-light writing; sometimes incomprehensible rapid-paced dialogue; skillful cinematography; and fine acting. But there the similarity ends.

Considering the fact that ''Bay City'' makes its entrance with a great deal of fanfare engendered by its ''Hill Street' genealogy, it is only fair to compare the two. ''Hill Street Blues'' deals with an urban police force and the people who make up a precinct. The issues are universal, vital, fascinating. ''Bay City'' is not about baseball; it is about the people who play baseball.

There's not much actual playing in the first two episodes (which I have previewed), but there is a lot of talk about trades, behind-the-scenes deals, and maneuvers by the owner, manager, scouts, and players.

If the intricacies of AAA, AA, and A minor-league teams are not of great interest to you, the series attempts to distract viewers with the rather intimate details of the private lives of the players and a few local citizens, as well as flashes of locker-room nudity. And you'd better be prepared to cope with the rather disgusting details of spitballs as well.

Thus ''Hill Street'' attracts its audience because, in addition to its skillful presentation, it deals with law and order and issues of vital importance to viewers, matters of life and death in many cases. ''Bay City,'' however, deals with basically trivial matters, because everything stems from what is in the long run only a game, a sport, of vital importance only to those who make it their profession.

Despite its surface sophistication, ''Hill Street'' is basically a very moral show with its own set of kind of enlightened puritanical standards. ''Bay City, '' on the other hand - despite the fact that one character continually rejects the early advances of a married woman - seems to be developing a curious set of standards on field and off, perhaps influenced a bit too much by the morality of professional baseball.

In the second segment, for example, the team's catcher is ostracized because of his allegedly ''villainous'' action in turning over the pitcher's illegal spitball to the umpire, who asked to see it. By ''Bay City'' standards - and according to this show by those of professional baseball - he should have dropped the ball in the dust to obscure the illegal action by the pitcher.

''Bay City'' is peopled by a varied group of talented, mostly unknown actors, all of whom are splendidly directed so that they become believable - if not totally distinguishable - immediately. It'll take some viewing before all of the players develop individual identities. But it is apparent right from the start that Michael Nouri (of the movie ''Flashdance'') in his role as the manager is bound to become a major television star - if the series lasts through the season.

Will it last? There should be enough baseball fans out there to get the show to first base. The big question for ''Bay City Blues'': Are there enough nonbaseball fans out there to get the base runner home?