If Bobby Carpenter handles himself as capably on the ice as he did on the Capital Club dais yesterday, he may, indeed, become the greatest American-born hockey player of all time.

Carpenter, announcing to the world that he had signed a contract with the Washington Capitals, was an island of sanity in an ocean of pomp and puffery. While talk abounded of family decisions and helpful advice, both legal and otherwise, it was obvious Carpenter had turned pro because he wanted to -- periord.

"The ultimate factor was that's what I wanted to do," Carpenter said. "Ever since I started skating, I've wanted to play in the National Hockey League. If I didn't do it now, when I had the chance, I figured I'd regret it later."

Carpenter, who turned 18 in July, will receive about $500,000 over the next three years to play hockey. Additionally, his contract includes provisions for his college education, probably commencing on a part-time basis at the University of Maryland in January.

Carpenter last week notified Providence College that he would not be using the grant-in-aid it had awarded him. The offical announcement of his decision to join the Capitals was delayed until yesterday, however, so the club could milk it to the maximum.

Television crews and reporters were on hand from both U.S. and Canada, and Carpenter gave 28 individual and small-group interviews following the formal session. Representatives from the White House and Maryland State House were present, as well as the congressmen from both Carpenter's home Massachusetts district and the Maryland suburbs, Carpenter's family, his high school coach and hockey great Bobby Orr, who has been advising the youngster.

A mimeographed seating chart listed all the dignitaries, including several Washington players. It was labeled "Second Revision." Considering all the accoutrements, includingh raw bar and open bar, "Second Coming" might have been more appropriate.

While praise was heaped on him from all directions, Capenter stayed on an even keel, fielding loaded questions with aplomb.

Asked whether he was the man to finally lift the Capitals into the playoffs, Carpenter said, "I've got to make the team first before I can help them make the playoffs."

Asked about the possibility of starting his pro career on the Capitals' farm in Hershey, Carpenter said, "If Max McNab and Gary Green feel I should start the season in Hershey, that's where I'll start."

Concerning his label as "the greatest American,' Carpenter said, "I just have to keep working hard and keep doing what I've been doing. It's going to be a challenge, but I like challenges. I wouldn't want to pass this one up."

Carpenter is not without a sense of humor and, asked what Orr had taught him, he cracked, "To take care of my knees, for one thing." It was damaged knees that forced Orr to retire.

Questioned on youthful loyalty to the Boston Bruins, the youngster drew laughs with: "When I was younger, we used to go watch them all the time." Then he added, "Right now I'm a Washington Capitals fan."

Orr had his little joke, too. Of the prolonged negotiations in which he participated along with attorney Jack Herlihy, Orr said, "I enjoyed the battle. It was a tough battle, you just have to look at Mr. Pollin here."

Owner Abe Pollin had a bandage over his left eye.

Carpenter, picked third in the June NHL draft, went higher than any other American; not so high as some thought, however.

NHL President John Ziegler, in a telephone tribute, noted that Carpenter was "the first U.S. player selected in the first round in the history of the league." That honor, of course, went to Mike Ramsey of Buffalo in 1979.

Herlihy was even farther off base in a phone call from Banff, Albert, calling Carpenter the first in the "100-year history of the National Hockey League," which was organized in 1917.

Then there was Michael Canning, who read a message from Maryland Gov. Harry Hughes, congratulating Carpenter on signing with "this distinguished organization." The struggling Capitals have been called a lot of things by their supporters, but that had to be a first.

Through it all, Carpenter smiled and said the right things. He nodded in agreement when Green, the realist coach, said, "We have lots of room on our hockey club for a good hockey player. But no matter how good, there's an adjustment period in the form of an adjustment to this league. I'll have to be patient. But Bobby is worth waiting for."

Carpenter will wear No. 10, formerly the property of center Rolf Edberg, who will play in Sweden this season while scouting for the Capitals.