NEW YORK -- CBS executive Kelly Kahl feels a little like a football player, all taped up and wearing pads, anxiously waiting in the locker room for the start of a new season.

Before he can charge onto the field, it might be worth a look back at the summer -- broadcast television's long offseason -- to see what lessons it might offer.

The summer's big story undoubtedly was Fox's "American Idol," which grabbed young viewers first and gradually became a hit. Nearly 28 million people were watching Wednesday when Kelly Clarkson won.

But those who follow the television business closely are more intrigued by two other numbers -- 53 and 38. Those were the average percentages of television sets tuned in to an ad-supported basic cable channel and one of the seven broadcast networks, respectively. That's right -- 38 percent for the old over-the-air broadcasters.

It wasn't too long ago, back in 1996, when they commanded nearly 59 percent of the audience in summer. Except for the years when "Who Wants to Be a Millionaire" and "Survivor" were hits, it's been a swift decline that accelerated this year.

Summer is when broadcasters' hold on the television audience is most tenuous.

In a startling sign of the times, this summer's most popular new scripted series, "Monk," was on cable (USA). ABC agreed to show "Monk" reruns, the first time a network ever made such an arrangement with a cable channel, and it quickly became ABC's most popular entertainment series.

Crave new shows

The "Survivor" and "Millionaire" experiences proved viewers crave new programming in the summer, and will leave back porches or beaches for something they like.

Yet the percentage of new programming offered by the broadcast networks this summer was exactly the same as in summer 2001, said Jack Wakshlag, TNT's research head.

When cable's Lifetime conducted focus groups earlier this summer they heard the refrain from viewers over and over again: There's nothing new on the broadcast networks after Memorial Day, so it's time to turn to cable.

Broadcast networks worsen their plight with special "sweeps" programming in May -- a period chock full of season or series finales and specials, said Tim Brooks, the network's research chief.

"By comparison, it's such an abrupt change in June that it seems like everything has ended," Brooks said.

Cable programmers know this, of course, and often schedule their most important new shows in the summer. Between "Monk" and "The Dead Zone," USA did this with particular effectiveness this year.

Increasingly, March and April have become relatively fallow months for the networks as well, as they plug in reruns so enough fresh episodes are available for May. Cable took advantage of that, too, introducing hits like MTV's "The Osbournes" and FX's "The Shield," and getting viewers in the habit of checking cable listings.

NBC was clearly the most aggressive network trying new things this summer. The game show, "Dog Eat Dog," and reality series "Meet My Folks" and "Crime & Punishment" were all moderately successful.

Kahl, the CBS exec, said the fall is when networks do most of their planning for the following summer, and they were thrown off-kilter last year because of the Sept. 11 terrorist attacks.

"We were really focusing on the season, and trying to salvage a few victories out of a difficult season," he said.