NEW YORK -- There's a curious thing about the art of tennis play-by-play on television -- like most other sports, the broadcaster follows the ball; unlike most other sports, the broadcaster doesn't broadcast as he follows the ball.

At least that's the way it's supposed to be.

At CBS Sports, which is in the midst of televising its 20th consecutive U.S. Open tennis championships, that's the way it is.

"I don't want to make it sound like it's complicated," said CBS sportscaster Pat Summerall. "We sort of have a policy that when the ball's bouncing -- when it's in play -- we simply don't talk. We don't do the oohs and aahs that some people do."

Frank Chirkinian, CBS Sports' executive producer for the U.S. Open, essentially has a shut-up-or-ship-out policy.

"I devised a rule years ago that, in effect, announcers will be informative and pictures will be descriptive," Chirkinian said. "Broadcasters get in trouble when they try to fight the pictures and become descriptive. That's when they tell you what you already know or can see; in essence, insulting your intelligence . . . "

"There isn't a damn thing to say when the ball's in play. There's nothing important to say. Yet, on other networks, I hear them talk over tennis points. It's absurd."

CBS' silent success is all the more remarkable because it uses a three-man booth -- Summerall with analysts Tony Trabert and John Newcombe. With an eloquently economical Summerall weaving in and out of the incisive, quick analysis of his partners, this is a rare case of three voices making a sound that's singularly sensational.

"That's because of Summerall and only Summerall," Chirkinian said. "Pat's more of a traffic cop than anyone else. He's the best at it. It's his total lack of ego."

For Summerall, a compound sentence virtually constitutes a speech.

"If I had my druthers," Summerall said, "there'd just be two {announcers}. But we've never had a problem."

Tennis broadcasting presents a couple of problems for play-by-play announcers such as Summerall.

Unlike other sports, tennis does not have as many natural spots in which the announcer will build up to a higher excitement pitch and raise his intensity level. There are no home run calls or game-winning touchdowns. Remember, the play-by-play announcer is not calling the action as it breaks, so there's no "And there's a backhand deep to the base line and, OH MY, Becker wins the set with a splendid shot!"

There often is drama -- match point in a superb match, for instance -- but even then, Summerall won't shift into overdrive.

"That's basically proper training," Chirkinian said. "I'll always say, 'Let it play.' Let the moment speak for itself. The theatricality of the situation is already on the screen. To shout over that is lunacy."

Also, there is that basic question of whether play-by-play is needed at all. With the cameras clearly showing everything and the graphics updating the score, the play-by-play broadcaster really is reduced to searching for other information to add to the story without cluttering it.

"Tennis is somewhat similar to boxing in that the mental aspects are fascinating," CBS sportscaster Tim Ryan said. "What I try to look for in a match is that subtle difference in domination, the point when a match can turn. Trends develop, and we seek them out."

"I find myself in tennis, more than anything else, searching for things to say," Summerall said. "Sure, there are 9 million things you can say about strategy, the individuals, the game itself. But finding the appropriate thing to say is difficult."

This is Summerall's 15th straight year of searching for the right phrases at the U.S. Open. "I replaced Jack Kramer," he said. "I had no training. They simply said, 'Hey, you're going to do the U.S. Open.' "

And Summerall agreed -- probably without saying a word.