With rain threatening and the Patriots and Red Sox on television, Jim O'Brien didn't know what to expect when he pulled into the parking lot at the Celtics training facility in Waltham for yesterday's annual season ticket-holder's barbecue.

``I was wondering about the turnout, and the turnout was fantastic,'' the Celtics coach said during the meet-and-greet, which included Celtics rookies Marcus Banks, Kendrick Perkins and Brandon Hunter, in addition to veterans Walter McCarty and Mike James.

Fans lined up for autographs and pictures, and several took a moment to gawk at the rookie hardware on hand - two Hummer H2 vehicles, a shiny black Cadillac Escalade and a black Yukon.

``It says a lot of our organization that so many people are here,'' O'Brien said.

An admiring Wyc Grousbeck, Celtics CEO and managing partner, credited director of basketball operations Danny Ainge with building a good portion of the enthusiasm.

``It's Danny Ainge coming out and saying, `I have a plan.' While we have Paul Pierce and Antoine Walker we should be trying to win the whole thing,'' Grousbeck said.

Yesterday's crowd also said a lot about expectations. Celtics management has been absolutely thrilled since a franchise-record 18,000 tickets were sold within the first hour that tickets went on sale Sept. 20, in addition to a record 37,000 over the weekend. Seventy-five percent of the sales were made over the Internet.