On the first full day of a visit by members of the International Olympic Committee’s evaluation commission, Mayor Bloomberg likened the 2012 Summer Games to “The Gates” and said: “There are a handful of people who don’t want change, but, like ‘The Gates’ show, it is fun to criticize, fun to find fault, but when it comes together, New York welcomes everyone, and celebrates it.”

“The Gates,” which had faced opposition, was seen by more than 1 million visitors in the first half of its 16-day run, which ends Sunday. Mr. Bloomberg, an early and enthusiastic supporter of the huge installation by the Bulgarian born artist Christo and his French-born wife, Jeanne-Claude, said at a press luncheon yesterday: “‘The Gates’ are the biggest story around the world, and it shows that if we had an event, everyone would be welcomed and participate.”

The 13 members of the Olympics evaluation panel spent the day sequestered on the second floor of the Plaza Hotel’s Baroque Room for a 10-hour marathon meeting with officials from NYC2012, who presented nine of the bid’s 17 “themes,” with the most time spent on sports venues, according to the deputy mayor for economic development, Daniel Doctoroff, founder of NYC2012.

“The mood was not an attack and defense, but very professional and very warm,” Mr. Doctoroff said at a press briefing last night. “We spent our time explaining, amplifying, expanding, and expounding.”

Today, the evaluation commission is to visit venues for 19 sports on a daylong bus tour. The plan includes a stop at Madison Square Garden, where the Olympic basketball tournament would be held – despite its owners’ vocal opposition to the proposed Jets stadium on the West Side over rail yards owned by the Metropolitan Transportation Authority.

“Some people are very good at separating the Olympics from the MTA rail yards,” Mr. Doctoroff said. “The Dolans are one of those people.” Charles Dolan is chairman of Cablevision, parent company of Madison Square Garden, and his son James runs the Garden and the teams based there.

Mr. Doctoroff stayed in the Baroque Room throughout yesterday’s proceedings, and Mr. Bloomberg attended the morning sessions. They and the other New York boosters sat at a semicircular table facing sweeping views of Central Park South and the orange art installation. The evaluators faced the NYC2012 officials and an oversized screen that showed a series of renderings of Olympic facilities and videos touting New York.

The Olympics’ principal venue, the domed stadium for the New York Jets that would serve as the Olympics stadium, has been the most contentious element of New York’s bid. Some of those who oppose the stadium on the far West Side requested a meeting with the evaluation commission to present their arguments. Mr. Doctoroff said the request “was under consideration” last night.

The evaluation commission heard presentations that included how the compact nature of the plan would allow 21 sports to be held within 10 kilometers of the Olympic Village. That bucks a trend in recent years of putting the Olympic Villages on the outskirts of the cities, the executive director of NYC2012, Jay Kriegel, said. The proximity would enable Olympians and visitors to take public transportation to the events, which will minimize costs and be more environmentally friendly, Mr. Kriegel said.

The usual drop in riders of mass transit during the summer is more than the expected increase in the number of visitors and Olympians who would ride mass transit as a result of an Olympics, so it would be easy for the transit system to handle the Olympics, Mr. Bloomberg said.

Whatever the outcome of the Olympic bid, five venues will be built in the city, Mr. Kriegel said: the Jets’ stadium, officially called the New York Sports and Convention Center; the Nets arena in Brooklyn; the Aquatic Center in Corona Park; biking trails in Fresh Kills, and an expanded Jacob K. Javits Convention Center.

“Seventy percent of sports will be held in venues that are already in progress or planned,” Mr. Kriegel said. That is important because the IOC emphasizes keeping costs down for host cities and likes to see venues for the Olympics that are otherwise in regular use.

Mr. Doctoroff said there had been no discussion of the need for a backup plan for an Olympics stadium if the Jets stadium planned for the West Side should fall through, and no plans for a backup for any other planned venues.

There has been no need for “major revisions to our plans yet, but we are only one-quarter of the way through the visit,” the deputy mayor said.

While the Olympics commission worked at the Plaza, 10 blocks away at Rockefeller Center a rally was being held, with 50 former Olympians and Paralympians. With tourists waving NYC2012 flags and a three-story sign on the front of 30 Rockefeller Plaza that read “Support the Dream. The Olympic Games in New York City,” a gold-medal figure skater, Oksana Baiul, performed on ice with the NYC2012 logo painted in the center. Similar publicity decorated the Plaza, with a truck driving around the hotel with a sign welcoming the IOC to New York, and flags and banners on the hotel’s exterior.

At Rockefeller Center, the mayor gave a short exhortation to the crowd, asking, “Who thinks it’s time to bring the world’s greatest sporting event to the world’s greatest city?”

Mr. Bloomberg followed his appearance at the rally with a speech at a press luncheon at Christie’s auction house, where he said the drive to land the 2012 games had been “decades in the making” and was “overcoming protests from nervous naysayers.”

It would be the “ultimate capstone to my life,” Mr. Bloomberg said, if his daughter Georgina, an accomplished rider, were to compete at the equestrian site at Staten Island in the 2012 games. She is aiming to make the 2008 Olympics.

The evaluation commission is staying through Thursday, before moving on to Paris and Moscow. The committee has already visited Madrid and London. After visiting all five finalists vying to be the host city, the commission will prepare reports on its visits for the entire Olympics committee, which is to make its decision July 6 at Singapore.