Every good basketball team has such a player. He plays in relative anonymity behind a couple of stars. He does the dirty work that does not appear in the box score. Only coaches, teammates and aficianados realize his value.

Marquette and North Carolina, NCAA finalists last season, had them, the Warriors in Jim Boyland and the Tar Heels John Kuester. Thursday night in Madison Square Garden, Georgetown will have Steve Martin when it plays Alabama in th ECAC Holiday Festival final (9 p.m., WEAM-1390).

The fans will be watching the Hoyas' big-name players, Craig Shelton and Derrick Jackson, and probably will pay little attention to what Martin, the 6-foot-4 1/2 junior forward, is doing.

Martin always guards the opposition's best scoring forward, regardless of size, when the Hoyas play man-forman defense. In a box-and-one, he held St. Bonaventure's Greg Sanders to 11 points.

Martin prides himself on his defense. But, after four games of this 7-2 season, he led the Hoyas in field-goal percentage, free-throw percentage, rebounds and asslists. He still tops the starters in shooting and rebounding.

It takes a mature person to sacrifice personal glory for the team. That personality is probably the major reason Martin is playing for Georgetown now, instead of one of the bigger basketball schools that recruited the former New Orleans high school player of the year. He did not want a slam dunk to carry him to a degree.

He grew up as the youngest boy in a sports-minded family of eight children. One brother played two seasons for the NFL's New Orleans Saints. Another had a tryout with the NBA's Detroit Pistons. Yet, Martin talks most proudly of his oldest brother, George Jr., who won a Purple Heart in Vietnam.

"For a young person," said Georgetown coach John Thompson. "he's very sensible. HIs ways are set, and he's very mature. And yes, it's always easier to recruit a kid who knows what he wants."

Sure, Martin said, he dreams of an NCAA championship, with him making the winning basket. "Doesn't every player dream that dream?" he asked this morning at breakfast.

"This team can win the national championship," Martin insisted. "We have as much talent as any team in the country."

It should be noted that Martin does not usually dream dreams that go unfulfilled. He does not clamor for pro-basketball stardom, fancy cars or big salaries. He married shortly after high school graduation and wants to live comfortably, but not extravagantly, as a certified public accountant specializing in corporate taxes.

"In high school, we knew that if we didn't hit the books, we couldn't play anyway," Martin said. "Some of the colleges who wanted me were just built around basketball. I wanted a degree, and a good degree, because when my eligibility is over I'll have to find a job in order to eat, sleep and be comfortable.

"A degree is not just a piece of paper. It means a lot more when you go out to get a job and are competing, because the world is built more and more on competition nowadays. The background that you have are things that will hold up. Just to play basketball really isn't enough. You have to do more."

A year ago Georgetown and Alabama played in the first round of the Carolina Classic, and the Tide won, 66-64. Georgetown had a five-point lead and the ball late in that game only to becone too cautious. "It's like figtin Ali," Martin said. "You have to be the aggressor. You can't lie low and wait. You have to go after him because he is the champion" . . . Georgetown again is expected to play a lot of zone defense it gets the lead. Last year, 6-11, 255-pound Tom Scates neutralized high-scording Reggie Kind, but Tide guards Robert Murray and Anthony Scott shot better from the outside than Thompson thought they would . . . Alabama will take a 6-2 record into this game will road losses at Purdue and Indiana, and with victories over Michigan, Missouri, South Carolina and Princeton (twice) . . . Princeton, 4-5 with the losses by a total of 12 points, will play Holy Cross, now 6-1 after Tuesday's 7-65 loss of Georgetown, for third place.