Any televiewers who had not realized that the World Series is being broadcast this year by ABC rather than NBC, the network of so many Octobers, became aware of the change abruptly Tuesday night. Quick as you could say "fall classic," there was His Royal Heinous Howard Cosell subjecting yet another of our institutions to his unique verbal blight.

Game 1 - in which, if you somehow managed to miss it, the Yankees beat the Dodgers, 4-3, in 12 sensational innings - was too good to be ruined by Cosell's pompous soliloquies. But his blabbering did detract considerably from the otherwise successful debut of color man Tom Seaver and the capable play-by-play of Keith Jackson.

Three is a crowd in any broadcast booth, especially if one is Cosell, the unchallenged national irritant.

Undeniably, ABC did some good things in its maiden Series telecast, which lasted four hours. It relegated the team's hometown broacasters to the pregame show, where they could do minimal damage, instead of giving them 4 1/2 innings of play-by-play as in autumn's past.

The camera work, direction and replays were generally good, although the standard set by NBC's veteran director, Harry Coyle, is almost unapproachable.

Jackson is professional and competent, if unspectacular, and given to a few too many cliches ("Steve Garvey lays down the bunt for a base hit, and he's on with his first safety of the night.")

Seaver, the perennial all-star pitcher traded by the New York Mets to the Cincinnati Reds this summer - is an attractive new expert witness. He's knowledgeable, pleasant and able to mix up his stuff: an anecdote here, an earnest observation there and a tongue-in-cheek aside when he's ahead on the count.

But Cosell negated the positive by being himself, which means he clogged the others' air space with pronouncements such as:

"I must say, in perspective, that battered Yankee pitching staff appears to have been resuscitated by the re-emergence of Mr. Gullett."

"With the experiences that Jackson has had in right field this year, I think most Yankee fans would consider it felicitous for Rivers to take the ball."

"Reggie is not beguiled by the current approving roars of the crowd. He has heard other kinds of roars."

Where have you gone, Joe Garagiola? Our nation turns its lonely ears to you.

Even though Jackson and Seaver could undoubtedly have done a better job without Cosell, they would have been hard-pressed to match the job Jawing Joe and Tony Kubek did for NBC-TV in the recent league playoffs. Garagiola and Kubek may be the best team doing regular commentary on any sport.

Even those who tire of Garagiola's tongue that launched a thousand quips appreciate his irreverent love for the game, and Kubek is a superlative color commentator, truly an analyst rather than a cheer-leader or apologist.

Seaver has the potential to be as good. He is handsome, intelligent, articulate. Much like Tuesday's starting pitchers, Don Gullet and Don Sutton, he was shaky in the beginning but then settled down and became increasingly effective.

In the early innings, he spouted too much gee-whiz, oh-wow, marshmallow fluff, repeating ad nauseum that Catfish Hunter has been there before, the Dodger organization teachers the fundamentals and true professionals stay cool under pressure. But as he relaxed with the passing innings, his commentary became progressively more incisive, sinsightful and honest.

After Jackson and Cosell had ponderously discussed the potential of walkie-talkie for on-field spying, Seaver giggled, "You don't think they'd try to steal signs down there, do you? That's why they don't have flash cards."

Gullett cruising in the eighth inning. Seaver observed: "In the morning paper today, Keith, Gullett said he'd be able to pitch but he didn't think he'd be 100 per cent. I don't know if that was a psych job or what, because he has done a fine job . . . "

On the critical, controversial play in which Dodger Steve Garvey was called out at home by umpire Nestor Chylak, Seaver was superb. "The umpire was out of position in my estimation," he said. "He was up the line, instead of waiting at home plate."

Coswell, predictably, could not remain silent. Summoning his most solemn tones, he gave his benediction: "That's telling it like it is."