THE NEW sport in the United States is television ratings. Every week the newspapers print the box scores concerning what network had the biggest share of the viewing audience. Since there are only three networks the game gets pretty boring. The only reason people keep watching it is that so many executives' lives are at stake.

In football there are enough teams so that if you come in first, second or third it is not the end of the world. But in television, being first is everything, coming in second is embarrassing, and ending up third is a mortal sin.

The fact that all three networks are making zillions of dollars has no effect on their standings. This fall, ABC is No. [WORD ILLEGIBLE] NBC is No. 2 and CBS is No. 3. Because of this, heads are rolling at NBC and CBS. Grown men in Brooks Brothers' suits are throwing themselves in [WORD ILLEGIBLE] of commuter trains. Others, who used to travel around the country in private company jets, are now taking the bus to their new homes in the South Bronx.

My wife, who doesn't know how the game is played, thinks by switching her dial she can save a network executive's life.

The other night we were watching a TV show on ABC and she said, "Why don't we switch to CBS?"

"What for?" I asked.

"They need the business," she replied. "I just read they were No. 3 in the ratings."

"We can't help them by switching the dial," I told her.

"Why not?" she asked.

"Because we don't have a black box. You see, the ratings hinge on 1,200 homes. Mr. Nielsen puts a black box in each one of them, and then on the basis of that he knows how many people in the United States are tuned in to any particular show."

"But suppose we're not watching the same show as the person who has a black box?"

"That's not Mr. Nielsen's problem. He has to assume that we are watching the same program as the person with the black box. That's how the ratings are made."

"Well, why don't we get a black box and help out CBS and NBC? I don't see why ABC has to be always first."

"You can't get a black box just by asking for it. Mr. Nielsen decides who gets the black boxes and who doesn't. If everyone had a black box Nielsen would never be able to tally the results. He doesn't have the staff to check 100 million black boxes. In fact he'd go broke installing them."

"I wonder who has our black box?" my wife asked.

"What do you mean, who has our black box?"

"Well, somewhere out there in America someone has a black box, and Nielsen assumes whatever he or she is watching we're watching, too. If we could find out who the person is we could call her and tell her what network we were tuned in to just in case she was viewing something else."

"Nielsen doesn't tell anyone who has his black box. He makes people take an oath of secrecy when he puts one in their house. Otherwise everyone would be calling them up and they wouldn't have time to look at television."

"It's hard to believe that so many jobs and so much money are at stake because of 1,200 little black boxes. What would happen if someone with a black box watched public television instead of a network show?"

"Nielsen would probably come to the house himself and rip it out of the set, and he'd see to it you never got a black box again."

She thought about it for a moment and then said, "I'm glad we don't have a black box. I don't think I could stand the pressure."