As a terminally mediocre weekend tennis player -- I once had my only service ace of a match nullified because my opponent hadn't arrived on the court yet -- I always have been fascinated by the quality of tennis the world's best players can generate. These fellows who could beat me, 6-0, 6-0, 6-0, while wearing ankle chains and carving a turkey all at once.

In recent years, I've become equally astounded by CBS Sports' unyielding devotion to the U.S. Open. From only 6 1/2 hours coverage in 1972 to 13 hours as recently as 1976, CBS now gives us 36 1/2 hours of the nation's premier tennis event. Hollywood's finest scriptwriters might have trouble filling 36 1/2 hours dramatizing, say, the New Testament, but the U.S. Open's live drama and taped late-night highlights provide CBS with a fine two-week showcase.

"I know CBS is not in this for charity or good will. It's not a nonprofit organization," said David Winner, producer of CBS' U.S. Open coverage. "The network's making money off it or it wouldn't devote so much time to it."

In truth, the networks don't do much tennis anymore. ABC does a couple of tournaments a year, CBS does three tournaments other than the U.S. Open and NBC does six tournaments, including Wimbledon and the French Open.

Over the past several years, the networks have made a fundamental adjustment in how we view tennis matches. More often than not, we are shown the low end-court camera -- a ground-level perspective -- rather than the traditional high end-court camera. For my money -- which, admittedly, is not much and is mostly tied up in municipal bonds -- I'll take the high shot because it gives a clearer picture of the entire court. The networks disagree.

"We like to jump right into the living room and give a true sense of how fast that ball is traveling," said Tony Trabert, CBS' tennis analyst, in explaining the ground-level preference. "That's the one thing the average viewer doesn't appreciate -- the speed of it all."

"It's the only shot that gives you an indication of the power of the strokes," said Ted Nathanson, NBC's coordinating producer of tennis. "You can't see the far baseline, but it really doesn't make a difference. On a critical point, something like match point, I go up (to the high shot) because you want to see the call."

Because of the time available, CBS does a good deal of features and studio work during its U.S. Open coverage. It's far different from the network's coverage of golf's premier event, the Masters, where it's bang, bang, bang, golf shot after golf shot, with little attention to personalities and features.

"We have features targeted for this opening weekend," Winner said. "I don't expect people are going to watch 5 1/2 hours of tennis this weekend other than my relatives. The show has to be paced."

Thus, between live match coverage, CBS will give us interviews with John McEnroe, Jimmy Connors, Yannick Noah, Pancho Gonzales and Gabriela Sabatini.

Even though CBS' Winner and NBC's Nathanson agree that televised tennis coverage generally is excellent, there's the usual network grumbling that the other guy doesn't do it quite as well.

Winner: "We have a time zone in our favor (as opposed to Wimbledon). This tournament all happens live. When (NBC) is at Wimbledon, they don't control the cameras and coverage as much. We're the home broadcast team at the U.S. Open. I think we have a stronger studio operation. I don't even think they have a studio operation."

Nathanson: "(CBS) will cut in the middle of the point very often. They'll show you the master shot, then a closeup of the far-court player, then back to the master shot. You have to be very, very careful that the ball's in the picture. Often, if the ball's hit out, you won't see where the ball is.

"They'll also take a closeup of a man volleying at the net, then cut back. I don't think you can do that accurately. I find it disconcerting."

Nathanson's points are well-taken. In most sports, there's a tendency to switch cameras in mid-action too often. In baseball, for example, one camera will show us a ground ball hit to the shortstop, but after the shortstop throws to first base, the director will switch to a closeup angle of first base at the last moment, making it difficult to view the play.

Likewise, CBS' tendency to switch cameras often hurts the continuity of our viewing and jumbles each point needlessly.

But you can be the judge of that. Almost certainly, CBS is televising the U.S. Open at this very moment.

Doug Flutie, who won the Heisman Trophy with Boston College last year, yesterday was signed as a studio analyst for the ABC-TV network's College Football Association broadcasts this season. He will make his debut Monday night during the Alabama-Georgia game.

Flutie, who recently completed his first professional season as quarterback of the U.S. Football League's New Jersey Generals, will join host Jim Lampley and Beano Cook to provide "an added special dimension . . . a unique and contemporary insight into the college game," said Chuck Howard, vice president for production with ABC Sports.

Flutie signed with ABC for one year. The financial terms of the contract were not disclosed. He is scheduled to complete his degree in communications this fall at Boston College.