The scene at the Seneca Valley High football field was fervent a week ago. Players were whooping loudly, jumping in the air and pounding each other's shoulder pads and green helmets prior to their Maryland 3A quarterfinal against Wilde Lake. The marching band formed a human tunnel for the team to run through, while nearly 3,000 fans rose to their feet to cheer in tribute and anticipation.

As the team gathered near the goal post, Screaming Eagles Coach Terry Changuris looked down and noticed that the small orange cone marking the back of the end zone was about an inch in front of the boundary. The players broke the huddle and wildly burst through a paper banner. As they raced past band members and cheerleaders onto the field, Changuris bent down and gently moved the cone to the white end line before running onto the field with the team's remaining members.

This coach has an eye for detail. Add that to Changuris's intense commitment and his structured approach toward developing the program, and the mix has created a powerful winning tradition at Seneca Valley. The Screaming Eagles are 11-0 this season and have held sole possession of The Post's top ranking since the beginning of the 1998 season. Changuris's teams have won 37 straight games, including two consecutive state titles, entering tonight's Maryland 3A semifinal against seventh-ranked Damascus (10-1).

Changuris, 47, has been at the Germantown school since 1976 and became head coach in 1988. His teams were 6-4 in his first two seasons, but the program flourished in the nineties. Since the decade began, Seneca Valley has won 90 percent of its games overall (111-12) and has collected five state titles.

The success has forced Changuris to make sacrifices. He said he and his assistant coaches "do not have any social life" during the season. On "off-days" earlier this season, Changuris was invited to his niece's christening and to the wedding of a former player. He declined to attend. Instead, he spent the time preparing for upcoming games.

"I would love to do family things, but coaching is a total commitment," Changuris said. "I was very close to the kid who just got married, and he got married at my church. But I told him that I had given his team my total attention. Why should I not do that for this team?"

Changuris's attitude was shaped by the events of one weekend in the fall of 1990. That season, he had decided not to watch Randallstown High play the week before the Screaming Eagles were to face the team in the state playoffs. Instead, he took the day off. But Randallstown turned out to be a much faster team than Changuris and his assistants had prepared for after viewing game films. Randallstown defeated Seneca Valley, 33-21.

Since then, Changuris has insisted he and the staff attend games every Saturday afternoon. They try to see teams on the Screaming Eagles' schedule early in the season. But by midseason, the staff begins to calculate the Maryland playoff power points, which determine seeding for the postseason, and tries to figure which teams will advance beyond the regular season. Changuris saw Wilde Lake three times this season.

The work came in handy. Seneca Valley played the Wildecats in the first round of the playoffs last week and won, 49-11.

Each week, game plans are hatched at Changuris's Frederick home at 9 a.m. on Sunday. There, the 10 coaches meet to review the previous week's game films and the upcoming opponent. Because of the size of the group, Karen Changuris, Terry's wife, turned the living room into a second television room so the offensive coaches could watch film in one part of the house and the defensive coaches could gather in another.

"The coaches always come over and talk about guy-stuff, then they settle down and break down the films before I serve a big lunch," said Karen Changuris, who is a guidance counselor at Seneca Valley. "They are usually there until four or five in the afternoon. Terry does not have much of a social life during the season. Instead, he gives his total attention to the team."

That attention is focused in unique ways. Changuris has not held an intrasquad scrimmage during the season since 1989. At the time, he said the coaches enjoyed analyzing the hitting between linebackers and the offensive line.

"We thought it was cool to see them hit," Changuris said. "But by the end of the season, our offensive linemen were all hurt. . . . We realized kids only have a certain number of hits in them, and it's better to save those for games."

In the early 1990s, the coaches began having what they called "laid-back" practices during the season. They created "stations," which are five- to 15-minute sessions during which coaches teach the players certain facets of the game and the tendencies of their upcoming opponent.

On the first day of practice each fall, the first station is spent on passing drills and learning the hitch pattern, one of several passing plays that has helped senior quarterback Chris Kelley set a school record for touchdowns (25) this season. The Screaming Eagles have outscored opponents 444-70 and is seven points short of breaking the all-time school record for points in a season.

That strategy is the first drill on the second day. And the third, and the . . . .

"Sometimes practice gets boring, both for the kids and honestly sometimes for the coaches," Changuris said. "But we think it is important that the kids know what to expect from practice. We just go over things over and over and over again. When people come to watch our practices they leave very disappointed, saying to themselves, 'If this is the number one team in the area, then this area must stink. These guys do not do anything in practice.' But the best coaches are also teachers, and we spend a lot of time teaching and not yelling."

That effort is appreciated by the players. "We have really good coaches who prepare us for everything," said Clint Pitts, a senior starting defensive end. "Sometimes the coaches are more fired up for games than we are, and that gets us more fired up and intense. . . . What they tell us is almost always right."

The football staff does not have much margin for error. This current team has one player listed at more than 235 pounds. Four players weigh more than 230. The offensive line averages around 215 pounds per player.

Or, as offensive line coach Bill Plante said, "We are mostly a speed team since we do not have a lot of size. Basically, we are winning state titles with a bunch of neighborhood kids."

And that neighborhood gets smaller and smaller. Earlier this decade, Seneca Valley's enrollment nearly was cut in half when Quince Orchard High opened nearby. Two years ago, Northwest High opened just a couple miles down Great Seneca Highway. Both times, the new schools took dozens of players who would have played for the Screaming Eagles.

Northwest finished 9-2 this season and made the 2A playoffs. The team was led by quarterback Brian Shaw, running back Raymond Custis and tight end George Hackey, players who all began their careers at Seneca Valley and likely would have played for the Screaming Eagles this season had they not transferred.

Despite the losses in personnel, Seneca Valley keeps rolling. Even if it does not send players to Division I-A football programs--currently there are no Screaming Eagles playing for I-A colleges--the coaching staff believes it is able to get the most out of its players.

"It used to bother me that colleges would not take any of our kids," Changuris said. "But really they are looking for kids that are bigger than the ones we have. I am sure that Clint Pitts and [defensive end] Damian Hall are good enough to play in college, but they would have to gain 60 pounds and not lose any speed to do so." Pitts is 6 feet 3, 215 pounds; Hall 6-5, 200.

So Changuris aims to attract players who will play for tradition more than a chance to make a college team.

"I did not come out for the team as a freshman, and the whole reason I came out as a sophomore was to win state championships," said Rafael Mason, a senior running back. "My cousins played here and they always talk about it and I wanted to be part of it as well."