PLEASANTVILLE, N.Y. -- Before you get to what football people like to call The Year After, you begin with The Day After. So here came the veterans of the world champion New York Giants reporting to training camp. They marched in, many wearing Super Bowl XXI rings, preening like proud peacocks and insisting that, yes, everybody's still got a hungry heart.

Five Giants players wrote books during the offseason, as did Coach Bill Parcells; quarterback Phil Simms did several football videos. It just goes to show that if you win enough games, dump enough Gatorade on your coach, have your running back rush for more than 1,500 yards, allow your quarterback to become Mr. 22-of-25 in the Super Bowl and send your nose tackle into the grandstands to hug his kid for all the cameras to see, opportunity will more than knock. It will break down your door -- especially if you do it all under the world's greatest microscope, New York.

So on what officially was The Day After, the Giants' truest personalities emerged. Big Leonard Marshall, the famous author/defensive end, happened to saunter past one local sportswriter at Pace University and, with a scowl, said, "I didn't like what you put in the paper about me. I'm not talking to you." And he kept walking.

Marshall waffled nose tackle Jim Burt in his new book, writing about Burt's "ego being so big and me not wanting to deal with it." So much for camaraderie. But as guard Chris Godfrey said, "I think people know Leonard well enough so that maybe his remarks are not a surprise and they'll let it roll off their back."

Then there's the matter of the book written by Coach Bill Parcells ("Autobiography Of The Biggest Giant Of Them All"). Parcells kindly wrote, "George Young and I are living proof that a general manager and coach don't have to love each other to work well together." This was Young's response: "I don't read books without bibliographies."

Then there was the case of all-pro linebacker/author Lawrence Taylor. Take history's linebacking greats -- Sam Huff, Dick Butkus or Ray Nitschke -- and their on-field instincts and rage all pale to that of Taylor. Taylor called to order a brief one-minute news conference on The Day After. He permitted no questions from the media. Taylor then ripped the press for what he believes to be their mistreatment of his "L.T. Living On The Edge." He said sternly, pointedly, "Guys, I'm not gonna let you destroy me." That's L.T. as in Looking Tough.

Yet not everything is a sensitive subject with these Giants. Witness Phil McConkey, the wide receiver, former Navy helicopter pilot, erstwhile Super Bowl hero and, of course, the co-author (with Simms). McConkey was in a gleeful mood on The Day After and why shouldn't he have been? The Giants may have drafted three wide receivers in the first four rounds, but McConkey, 30, doesn't seem fazed. He admitted he earned more than $1 million with offseason promotions, speaking at so many banquets that, he said, "when I think back I can't remember all of them."

Further, McConkey's been plugging Rep. Jack Kemp's presidential drive and said someday "maybe I'll be his Secretary of the Navy." A year ago, the Giants cut McConkey and he said at the time he'd play for any team (which he did, for Green Bay, before returning to the Giants in a trade). Now McConkey says if he gets cut by the Giants, he'll just move on, perhaps to the speaking circuit. And who says players aren't changed by Super Bowl success?

Then there's Young, who as general manager is as responsible as anyone for the Giants' rise. When he came for his job interview with the Giants nine years ago, Young checked into a New York hotel using the name of Wayne Rosen, who then served as Commissioner Pete Rozelle's part-time driver.

Young smiled as he spoke of his Super Bowl fame: "I can say I knew that my anonymity was broken when I was recognized in a dirty book store in Manhattan. I was browsing and the guy behind the counter said, 'Isn't your name George Young?' I said, 'Never heard of him' and left."

And so perhaps you might have thought that winning their first world championship since 1956 would have changed these New York Giants. Or maybe you thought that distractions would make them fall in line with the 49ers, Raiders, Redskins and Bears as defending champions who were unable to repeat their title.

Not on your life. Or so they say. "The Super Bowl is past," said linebacker Carl Banks, "and there's nothing worse than old news."Simply the Best

From start to finish last season, the Giants were the best team in the National Football League. They finished 17-2. They haven't allowed an opposing running back to rush for 100 yards for the past 27 games. At one point, they stole six consecutive wins by a total of 22 points, then exploded to win their last five games by a total of 132.

Their victory formula was Lombardi-esque: a strong running offense led by Joe Morris and a swarming, pressure defense led by a corps of linebackers. Taylor, Banks and Harry Carson (with capable, sizable backups such as Gary Reasons, Andy Headen and Pepper Johnson) were the 1986 kings of the football jungle. They are all about 6 feet 3, 240 pounds and plenty mobile, and you can bet the rest of the NFL now will try to emulate their style.

This is not to imply that Simms didn't contribute last season. In fact, at the most critical moments, the quarterback produced in a big way. Simms since has talked about how his sterling Super Bowl effort ought to ease the can't-win-the-big-one catcalls. Even in their dreams, most quarterbacks would settle for completing, say, 20 of 25 passes. Simms did better than that in the Super Bowl.

McConkey said: "I remember sitting down to breakfast with Phil the morning after the Super Bowl. Neither of us had gone to sleep. We'd just done 'Good Morning America' and 'The Today Show' and I'm looking across the table and thinking, 'Here's a guy who had the greatest Super Bowl of any quarterback in history. I mean there was Namath, Starr, Montana, Staubach. And he was better than all of them . . . ' "

Forever, though, it seems doubts will plague Simms, who is 30 and entering his ninth season. "Phil's got to do it again before people are convinced he's the guy," New Orleans General Manager Jim Finks said. "I'm not saying he can't do it. They way he finished last year, he should come in with a lot of confidence this year."

Strange things have happened to the NFL's defending champions in the '80s. For one thing, they have suffered injuries, hordes of them. For another, the fourth quarter seems to become a trouble spot for the defending champions. Instead of accelerating, they have seemed to recede near game's end. The same players simply haven't played the same way in The Year After.

Maybe that's been due to a loss of fire or maybe it's just that other teams have been more inspired to beat the defending champion. (The Redskins, for example, lost three times to the Giants last season and some of their coaches are still burning from what they perceived to be public gloating by certain Giants coaches after the second victory over Washington.)

Giants safety Kenny Hill said that when times get difficult this season, "people inevitably will say it's happening to us because we are the defending champions. We can't listen to them." No NFL team successfully has defended a Super Bowl title since Pittsburgh in 1978-79.

Young said: "I really think that's happened because there hasn't been a dominating team. I don't really buy all that distraction stuff. Dominating teams overcome distractions."Staying in Condition

The Giants, to a man, stress that they have been devoutly loyal to strength coach Johnny Parker's offseason conditioning program. McConkey accents the point by saying that he and Simms were working on a football video in southern California in early April and had an invitation to fly to Las Vegas to see the Leonard-Hagler middleweight fight.

"We could've flown a private jet. We had offers for a private this or private that, front row seats and everything. But we didn't go," McConkey explained. "The fight was going on and we were lifting weights at Mesa {Ariz.} Junior College. In fact, we had to break into the {weight} room just to get in. Phil and I took turns calling SportsPhone to get the round-by-round results."

Young, of course, has an answer for all challenges. If an NFL players strike occurs, the Giants will have an advantage over other teams, Young said, "because we're already a 'made' team." And what about the pressure on the Giants if they have a 3-2 start (New York opens with Chicago, Dallas, Miami, the 49ers and Redskins)? Said Young: "It's not like it would be the first time we've ever started 3-2."

Mark Bavaro, surely the NFL's most complete tight end, caught 66 passes last season even though defenses knew the ball was coming his way. "We'll have more output from our wide receivers this year," Young promised, adding that this should help Bavaro, too. And how much longer can we expect the 5-foot-8 Morris to escape major injury?

"Look, Walter Payton is this much bigger than Joe Morris," Young said, holding his fingers two inches apart. "And when Walter Payton goes into the Hall of Fame he'll still be this much bigger than Joe Morris." Again, he held his fingers two inches apart.

Perhaps the most symbolic series involving the Giants last season occurred early in Super Bowl XXI. Denver led, 10-7, and reached first and goal at the Giants 1-yard line. The Broncos failed to gain the necessary 36 inches on three running plays, then Rich Karlis missed a 23-yard field goal attempt.

That series is representative of why the Giants believe they can repeat as champions. It's a football truth that even the most successful offenses inevitably will get bogged down by glitches or by injuries to key players, but that defenses will remain fairly constant for some time once they become dominant. The Bears finished 14-3 last season primarily because of a defense that guaranteed, at worst, they would remain within striking distance during the game's final five minutes.

And this is the real book on the New York Giants: they've got an excellent defense. "I know once we get on the field we'll all play together," Banks said. "And that's how it's going to be."