The hallmark of Bobby Knight's basketball teams, from his days at West Point to his national champions at Indiana, is aggressive, man-to-man defense. The opposition gets pounded for 40 minutes.

Tonight, the Hoosiers play their first regular-season game in the East since 1975. Undefeated, 20th-ranked Georgetown provides the opposition in an 8 o'clock game at Capital Centre. Steve Martin, the Hoya captain, expects the Indiana defense to test Georgetown's discipline.

"It's a very psychological thing," said Martin, "knowing a team's going to come after you all out the whole game. Before you walk on the floor, you have to prepare and know what you're going up against. You know you're going to get a certain beating because they are a physical team. You have to be prepared to take that beating for a full 40 minutes."

In other games involving area teams tonight, Howard (2-1), which held a team meeting until 4 a.m. following Monday night's upset by George Mason, hosts Buffalo at 8; American U. (2-3) travels to Rider in search of its third straight victory; Catholic U. (1-4) hosts St. Mary's at 8, and George Mason (2-1) plays an 8 p.m. game at Mount St. Mary's.

At Capital Centre, where the main event will be preceded by a matchup of the Washington and Baltimore Dunbar high schools at 6 p.m., Knight will bring in a struggling, young team (2-2) that had been ranked among the nation's top 10 teams in some preseason polls.

The Hoosiers are playing good defense, holding the opposition to 38.6 percent field-goal accuracy. Indiana ranked third nationally in that category last season when it posted a 21-8 record and earned an at-large bid to the NCAA tournament.

Knight complained that the Hoosiers did not play hard -- another usual trademark of Knight teams -- when they lost two games in the Sea Wolf Classic at Anchorage. But Saturday against Morehead State, an average team at best, the Hoosiers held the Eagles scoreless for 19 straight possessions at one stage.

Obviously, Morehead cracked under Indiana's defensive pressure.

"More than physical toughness, you have to keep your concentration in a game like this," said Georgetown Coach John Thompson. "You can't afford to get careless in a game like this, and that's what their defense can make you do."

The other concern for Georgetown is the availability of 6-foot-11, 245-pound center Tom Scates. He missed the St. Bonaventure game Saturday with a sprained ankle and is questionable for tonight.

"We'll need his size in this game," Thompson said. "Plus, defensively Tommy is very important to us."

"We need him for his rebounding and his intimidation," said Martin. "He can block shots and he covers up for a lot of the (defensive) mistakes I make and our other people make. Against a big, physical team, his mere presence is a psychological boost for us."

If Scates can start, freshman guard Eric Floyd, who has scored 28 and 17 points in his last two games, will again become Georgetown's sixth man, a role Thompson likes for him so the Hoyas can substitute from strength.

Indiana is somewhat similar to Georgetown. The Hoosiers have two established stars, sophomore center Ray Tolbert and junior forward Mike Woodson. The other starters are likely to be 6-2 sophomore Tommy Baker at point guard, 6-5 freshman Randy Wittman at the other guard and 6-9 senior Jim Roberson at center.

The Hoosiers had some early-season ball-handling and leadership problems in trying to replace the leaders of last year's team, guards Wayne Radford and Jim Wisman. Like Georgetown, Indiana lacks established depth.

Capital Centre officials, who are helping in the extensive promotion of the game, are hoping for a crowd of 8,000 to 10,000.

At Howard, Coach A. B. Williamson said as many as two lineup changes could be expected for tonight's game against Buffalo, although he refused to say who would be benched. He termed the meeting until 4 a.m. a skull session.

"We were 20 points better than Mason and on nine of our first 10 fast breaks we turned the ball over," he said. "There's no need to panic, but we have not had a good game yet. Mason was probably the worst game of any team I've had. We've just got to get into it and play hard. We don't know the intensity you've got to have to play this game."

Williamson held a similar meeting, with a practice, after a similar-type loss to CU last season. The Bison responded by winning their next six games.