Boston's subway system doesn't have a yellow line. Neither do most hockey teams.

Sure, a yellow (or fourth) line will appear on the line sheets of most teams. But how often does RPI or Vermont or Minnesota send out its yellow line for combat?

Once a game? Once a blue moon?

When Harvard hockey Coach Bill Cleary's team is playing the kind of game he likes, he sends one line after another onto the ice. First line. Second line. Third line, Fourth line. Red line. Green line. Orange line. Yellow line.

As colorful as a rainbow. As hurtful as a runaway train.

No one works harder than the three kids on the yellow line," Cleary says. "They all play within the boundaries of abilities. They forecheck well. And when you tell them to take the man. boy, they take him."

Looking at their statistics, you would think that Paul Howley, Ed Presz and Craig Taucher--who make up the fourth line--are hockey's equivalent of the Three Mouseketeers. The trio has scored a combined six goals.

But if they be mice, they have a lion's roar.

"They're a tough line physically," Cleary says. "I want to tell you something--if they go after you, you're going to feel it."

If you sent five basketball players out on the court, and they didn't score, you'd be in trouble. But in hockey, scoring is only part of the game. Some lines serve other--less glamorous, it's true, but just as noble--purposes.

"A lot of teams will send two lines out and try to gun them at you," Howley says. "We wear the other team down. And we can be a threat if they're worn down."

Still, scoring is fun. And the fourth line would like to join the party.

"It definitely frustrates us," Taucher says. "A lot of times we come off the ice thinking we had a good game, but there's nothing to show for it. We haven't gotten a lot of breaks."

Howley, Presz and Taucher (all juniors) played on the JV team on and off for the past two years. But this year, they moved en masse to the varsity. Since December--when Cleary first put them together--they've played hard-hitting hockey.

"Over the past 10 games, they've been the most consistent line, Harvard Captain Steve Armstrong says.