Minutes after Friday night's presidential debate ended, the McCain campaign had posted a video on YouTube.com enumerating the times Sen. Barack Obama noted that Sen. John McCain was "right" about something -- seven.

At 8 a.m. the next morning, the Obama campaign unveiled its own new ad: "Zero" -- the number of times Mr. McCain mentioned "the middle class" during the 90-minute matchup at the University of Mississippi.

Both campaigns scrambled this weekend to score political points after a debate that was full of substance and evasion, fumbling and occasional zingers -- but one, most pundits agreed, that lacked the crucial breakout moment needed to shake up a neck-and-neck race.

"There were no defining moments, no gotcha moments, no moments at all that could have moved things off script -- which means we still have a very close, competitive race that could be won by either candidate," said Terry Madonna, a political science professor and pollster at Franklin & Marshall College in Lancaster.

Based on his own polling and other surveys, Mr. Madonna said, "About 15 percent of the voters remain genuinely in play and I don't think last night moved very many of them."

Nonetheless, in what has become a predictable post-debate ritual, both campaigns deluged reporters yesterday with cherry-picked "reviews" from television analysts and newspaper editorial boards declaring their candidate the winner.

Those efforts to massage public perception and jolt the campaign out of its stasis has taken on particular urgency this year, given the closeness of the race and the fact that the actual pool of undecided voters is much smaller than many polls reveal, said Jeff Berry, a professor of political science at Tufts University.

"When pollsters push too hard, sometimes people say they're undecided when they really aren't," he said. Given this race's uncertainty, there may be a lot of that going on.

Still, while there may not be many wavering voters left, "the public clearly regards Sen. Obama as the winner," he said, noting that a series of instant polls -- by CNN, CBS, plus focus groups on Fox News and by Republican pollster Frank Luntz -- consistently gave the edge to Mr. Obama.

While the particulars of the debate itself may soon fade from public consciousness, "Mr. Obama achieved the one thing he had to do, which was convince viewers that he would be at least an adequate commander-in-chief," he added.

"And with Obama leading narrowly in national polls up until Friday, McCain now has to figure out how to take that lead away from him."

Of course, that's just one political scientist's perception. While Mr. Obama may have come out ahead simply by holding his own, said Ken Heineman, a political science professor at Ohio University, Mr. McCain won the expectations game -- an important plus, given that he had been in danger of losing it during last week's chaotic events on Wall Street and in Washington.

"He wasn't tired or grumpy, but conversational, smiling, and kept emphasizing his experience in bipartisanship, which was an effective play for independents," said Mr. Heineman.

Both candidates made strong points on foreign policy, and Mr. McCain skillfully focused on taxes and spending cuts rather than on the Wall Street financial crisis, he said, while Mr. Obama "should have scored a knockout on the economy, which is such a 'gimme' issue, and he didn't."

"I'd say McCain won on the margins, but he didn't stage a knockout punch," Mr. Heineman added.

Mr. McCain planned to remain in Washington over the weekend to work on the financial bailout bill, his campaign said.

Mr. Obama, on the other hand, hit the campaign trail, hammering away at his opponent's debate performance.

"The truth is, through 90 minutes of debating, John McCain had a lot to say about me, but he had nothing to say about you. He didn't even say the words 'middle class.' Not once," Mr. Obama told a crowd in Greensboro, N.C.

At the same time, David Plouffe, Mr. Obama's campaign manager, was busy lowering expectations for the next few debates. Republican vice presidential nominee Gov. Sarah Palin -- who faces Sen. Joseph R. Biden Jr. Thursday -- is "a gifted debater," he told reporters in a conference call, while Mr. Obama will also be "the decided underdog" in a town hall meeting Oct. 7 in Nashville.

"[John McCain] is the undisputed town hall champion, and he's done more of them than any president in history," Mr. Plouffe said, adding that he would be "thrilled," if Mr. Obama can "escape unscathed."

He also conceded, though, that these debates may not produce much movement in the polls in the near future. While voters are now becoming very focused, many "may wait until even after the third debate to make their decision," Mr. Plouffe said. "But for those who do, we're confident we put more in our column than in John McCain's."

Tucker Bounds, a spokesman for the McCain campaign, said Mr. Obama failed a key test: showing voters he was capable of being commander-in-chief -- because he "failed to utter the word 'victory' a single time" during the debate.

"Despite that fact, his campaign launched a mad-dash of damage-control this morning attempting to claim a debate 'victory' for Barack Obama when he was clearly struggling to defend his record of lavish new government spending, higher taxes and failed foreign policy judgment."

In the end, this fixation on how many words were uttered -- or not uttered -- by either candidate, not to mention the emphasis on who "won" or who "lost," may be for naught.

Some debates produce ineffable moments that resonate with the public and, ultimately, define the candidate -- from Vice President Al Gore's condescending sighs in 2000 to then Gov. Ronald Reagan's head-shaking, mock-regretful "There you go again" in 1980. But it's important to remember that Sen. John F. Kerry "won" at least two out of three debates in 2004 with President Bush -- and then lost the election.

"Kerry came across as a technician, while Bush came across as a regular guy, and people identified with him," said Mr. Madonna. "On that score, I'd say that McCain did a much better job connecting with the voters, while on debate points, Obama won."

Nonetheless, he added, "by next week we may have completely forgotten all about this."

"To a limited extent I don't know if debates ever change anyone's minds," added Gerald Shuster, a professor of political communication at the University of Pittsburgh's Department of Communications. "They tend to reinforce perceptions of one's own candidate. If you already like one, chances are you'll think he did a great job."