Robin Roberts and Diane Sawyer co-host Good Morning America.

ABC / IDA MAE ASTUTE

At this point, no one could blame ABC’s Good Morning America for developing a Wile E. Coyote complex: Every time it gets so close to NBC’s Today that it can all but taste victory, its nemesis bolts off, leaving only the taste of dust.

No competition in television has gone this way for this long: As of last week Today led the morning ratings for 655 weeks in a row — more than 12 years. And nothing appears to be changing. Though Good Morning America made another run at Today in October, closing the weekly gap to about 200,000 viewers, the zoom-away move took place a short time later.

Now the gap is wide again, the biggest it has been in four years. Since the start of the year, Today is up about 3 percent, leading Good Morning America, which is down 6 percent, by about 1.2 million viewers a week. (The Early Show, on CBS, trails far behind the two other programs.)

“Any way you slice it or dice it, these are numbers you can’t ignore,” said Jim Bell, the executive producer of Today.

Matt Lauer, the co-anchor of Today for 12 years, said the program had emerged from “a period of a little audience experimentation” after the departure of his longtime partner, Katie Couric, to a point where the audience likes “the dynamic on the show.”

Meredith Vieira, Couric’s replacement, has “become much more comfortable” on the program, Bell said.

NBC offered several other reasons for the resurgence, including one bit of stunt programming (an “Ends of the Earth” project put the program’s hosts at the planet’s two poles and the equator to examine climate change) and coverage of the year’s two big news subjects, the presidential primaries and the economy.

One ABC executive noted that NBC had an advantage in being able to rely on its two sister cable channels to help cover those two topics — for politics, commentators from MSNBC and NBC News (especially Tim Russert, who appeared on Today more than 50 times this year, before his death last month), and, for economic expertise, CNBC reporters.

But Good Morning America has turned to its own strengths, including strategies like loading up with “secret scenes” (i.e., outtakes) from Desperate Housewives, when that series was hot, and with contestants from Dancing With the Stars, when that show exploded in prime time.

Other factors may also explain the ratings difference. Today has capitalized on the depth and popularity of its cast, especially Lauer. How strong is Lauer? A production executive from a competing morning program had no reservations.

“Matt is simply the best morning anchor in history,” said the executive, who asked not to be identified when praising the opposition. “He is perfect at the job. It makes me crazy.”

ABC executives offered other explanations for what their news division president, David Westin, called “a little hiccup” in the past year. These included disproportionate fallout from the Hollywood writers’ strike (because, they argue, ABC’s entertainment shows fare better than NBC’s, and prime-time strength can carry over to mornings, a strength ABC lost during the strike) and occasional disruptions as the program’s co-anchor, Robin Roberts, was treated for breast cancer.

“Our team was rarely together this year,” said Jim Murphy, the executive producer of Good Morning America. He said one result was that his biggest star, Diane Sawyer, was needed to handle hosting duties and was not able to cover as many major international stories as she had in 2006 and last year, when she reported from North Korea and Iran.

Murphy, of ABC, acknowledged that Today made gains during those Ends of the Earth trips in November, which coincided with a “green week” initiative at NBC and its parent, General Electric.

“It performed well,” he said. “They used their whole conglomerate to promote it.”

One consistent rationalization ABC offers for NBC’s morning dominance is that Today gets all it needs from a corporation desperate to maintain a morning lead because the network has little else working, and because it remains a particular pet of the NBC Universal chief executive, Jeff Zucker. He spent a decade earlier in his career as the Today executive producer.

No one at NBC disputes the importance of Today. Now stretched to four hours a day, it supplies almost as many hours a week as the network’s prime-time schedule. It also generates revenues of $450 million to $500 million a year. (Good Morning America earns less, with ABC saying only that its revenues are several hundred million dollars a year.)

Zucker does stay close to the program. The Ends of the Earth project was his idea, and he mandated the three-channel approach to political and economic reporting. Bell said that he was only too happy to accept the support the company gives Today And he did not apologize for doing everything possible to keep the program’s DiMaggio-esque hitting streak going.The Sawyer factor

Diane Sawyer’s role on Good Morning America has become something of a serial drama. She joined it in 1999, saving it from a disastrous downturn. Lately, questions have arisen about how long she will stay.

ABC News division president David Westin said Sawyer had given him no reason to think she would not remain.

“I have heard nothing from her otherwise,” he said.

Jeffrey W. Schneider, an ABC News senior vice president, said Sawyer declined to comment and would let Westin’s comments speak for her. But another network news executive, who has worked with Sawyer, said she had never gotten over losing out — twice — for the job of ABC evening news anchor, most recently when it went to her former Good Morning America co-host, Charles Gibson.

“She is so angry at the company,” said the executive, who requested anonymity because of the sensitivity of the issue inside ABC News. “They didn’t give her the job she deserves. They want her to stay in this job because it makes so much money. But to her it’s boring, it’s repetitive, and it’s cheesy to have to do all the things she has to in service of the company.”

Westin dismissed that analysis: “Hey, I get angry sometimes. But I have never seen Diane Sawyer more committed to the show.”