This was Friday evening, half an hour before the Pigskin Club gave its football awards for 1981, and the elusive Marcus Allen, the dashing tailback from Southern California, sat on the edge of a couch at the Capital Hilton, leaning forward to hear a question.

Someone said, "Have you won the Heisman?"

The winner would be announced the next night, live on television from New York, and the Heisman people must have made Marcus swear on a stack of O.J. Simpson photographs he wouldn't tell anybody.

So he said, smiling, "Man, this tux is tight." He scooted back on the couch. Impishly, he raised an eyebrow. "I really don't know who won it."

Well, where was he going from Washington? To, maybe, New York?

"I don't know," he said, neatly sidestepping the tackle.

Last night, Marcus Allen won the Heisman Trophy, as have other USC tailbacks: Mike Garrett, O.J. Simpson and Charles White.

If Allen wouldn't tell in advance, Jim McMahon would. The BYU quarterback, who shared with Allen the Pigskin Club's award for offensive work, said, "Up in New York last week, they told us Marcus was the winner, with Herschel Walker second and me probably third."

Infused with a thousand gallons of self-esteem, as most quarterbacks are, McMahon didn't seem all that thrilled with the Heisman results. More on McMahon in a minute.

In dreams, most backs can't gain 200 yards in a game. Marcus Allen averaged 212.9. His 2,342 yards broke Tony Dorsett's NCAA season record by 394. He led the nation with 23 touchdowns.

Not bad for a 6-foot-1, 200-pound fellow who came to USC to play defense.

"I knew about the Heisman ever since I was a little kid in San Diego," Allen said. "But I thought you could win it for anything. I'd play baseball and say, 'I'm gonna win the Heisman.' The first time I knew it was for football was when O.J. won it."

That was 1968. Marcus Allen was 8 years old.

"If I would win it," he said, "it would feel good because it feels good when you set your sights on something and do it. Last year, I said, 'I'm going to win the Heisman.' "

As a freshman, with White injured, Allen became a tailback for a while. He liked it. After a season as a fullback blocking for White, Allen took over.

"It's amazing, considering how many times I carried the ball, that I didn't get hurt at all," Allen said.

How many carries?

"Four hundred," he said.

Come on, Marcus. You're not talking to any dummy.

"Four hundred and six carries," Allen said, smiling proudly.

Well, the very essence of journalism is to check the facts.

Sure enough, Marcus Allen was wrong.

He carried 403 times.

That's 36.6 carries a game.

Some journalists don't get off their duffs 36.6 times a day.

"God is smiling on me," Allen said. "I never got hurt. I try to avoid people who want to tackle me."

Of the Trojans' distinguished tailbacks, only Simpson was a great pro. Some theorists say USC uses up tailbacks with all that work. Others say USC's offensive line is vastly superior to its opposition.

"I'm not worried," Allen said. "I'm not a negative-thinking person. I hope the future is bright for me."

Now, back to Jim McMahon, who attended the Pigskin Club's black-tie affair in a leather jacket and blue slacks.

"The Heisman was my goal for a long time," he said, almost churlishly. Quarterbacks believe it's more difficult to throw the thing 50 yards to a moving target than it is to hold it in your hand and just run until somebody knocks you down.

Still, McMahon confessed, "It was an off-year for me."

He threw for 30 touchdowns in 10 games. He set a college record of 44 completions in a game (seven touchdowns that day). He threw for 565 yards once. His average day was 27 for 42 for 355 yards and three touchdowns.

An off-year? "I had 47 touchdown passes last year," said the kid from San Jose, Calif., who chose BYU for its passing attack, not its academics, and now can't wait to get out of school and into the NFL.

McMahon missed 2 1/2 games this season. Also, eight of BYU's top nine receivers from 1980 had graduated. "So we were playing with freshman and sophomore receivers," said McMahon, who also says of himself, "I don't think there's a better quarterback in the country."

The pros say he'll go in the first round of the draft, McMahon said, and he doesn't argue. Look at touchdown passes, he said. "A lot of quarterbacks throw the ball well from the 20 to the 20 but they don't put it in the end zone and don't win. I put the ball in the end zone, and that's what it's all about."

In barely two seasons, McMahon threw 84 touchdown passes at BYU and accumulated 9,536 yards total offense. That's 1,279 yards more than the previous NCAA record, set by Mark Hermann of Purdue in four seasons.

"Yeah," McMahon said when someone said that is amazing.

It's nice, he said, to see rookie Neal Lomax at quarterback for St. Louis and his old teammate, Marc Wilson, starting in his second year at Oakland. Wilson and McMahon split work at BYU in 1979, but McMahon chose to redshirt in '80 rather than share the job again.

"It's encouraging to see them playing well, especially Wilson," McMahon said. "I feel I can play in that league if he can."

Marcus Allen, talking about the pros, only says he won't go to Canada. "I guess I should say I'd play anywhere in the Northern Hemisphere," he said, thinking of money talks coming up. "But the NFL has always been a dream of mine."