Regional basketball playoff action will begin today for area Virginia and Maryland schools, while the three-day Interhigh tournament gets under way at Coolidge.

In Virginia, Lake Braddock, eliminated in the first round of the Virginia AAA Northern Region basketball playoffs the past two years, will begin its mission to prove it deserves the No. 1 Northern Region boys seed when the Bruins put their 18-game winning streak on the line at home against last year's state runner-up Hayfield (8-14) at 8:30.

In other first-round boys games tonight, Mount Vernon (20-3) will play host to Robinson (13-9) at 8; Lee (20-4) will be at T.C. Williams (13-9) at 8; Annandale (19-4) will entertain Herndon (9-13) at 8:30; Chantilly (11-11) will be at South Lakes (21-2) at 8:30; Madison (18-5) will play at Fairfax (14-9) at 8:30; W.T. Woodson (6-16) will be at West Potomac (10-15) at 8 and Wakefield (13-9) will travel to Washington-Lee (18-5) at 8.

The Lake Braddock girls, with a 22-1 mark, are favored to win the Region. In a first-round game, the Bruins will entertain Hayfield (8-15) at 6:30. Annandale (21-1) will welcome McLean (13-9) at 6:30; West Potomac (11-11) will travel to W.T. Woodson (18-5) at 8; Wakefield (6-16) will play at Langley (19-5) at 8; West Springfield (13-9) will journey to Mount Vernon (14-8) at 6:30; Fairfax (17-6) will be host to Madison (17-6) at 6:30; Oakton (13-9) will play at Lee (21-2) at 8 and Chantilly (12-10) will travel to South Lakes (16-7) at 6:30.

The AAA Northwest Regional, which includes teams from the Commonwealth District, will begin play Tuesday. Group AA and A action will begin later in the week.

Ninety area Maryland teams will participate in regional tournaments. Girls games will be played Monday, Wednesday and Friday with the boys playing Tuesday, Thursday and Saturday except for AA III, which will play Friday instead of Thursday.

Among top seeds in boys play are Crossland and Springbrook in AA. Among the girls, Springbrook, Rockville and Friendly are top AA seeds. Mount Hebron defends its state title and 20-0 record in Class B.

Elsewhere in the area, Coolidge (25-2) has won the Interhigh League championship and, led by center Donald Hodge, will face Metro Conference champion DeMatha (25-3) for the City Title Sunday at Cole Field House. The Colts are the top-seeded team and received a first-round bye in the league tournament that will begin today at Coolidge.

Spingarn (19-7), which finished second in regular season play and also received a first-round bye, will join four other teams in the hunt for the tournament title or at least a berth in the final game in order to represent the league in the preliminary game slot Sunday.

In first round games today, Wilson (11-17) will meet Woodson (12-12) at 4:45 and McKinley (16-8) will face Eastern (11-12) at 8:15.

In the girls' playoffs, Wilson (22-3) and Coolidge (23-3) tied for the regular season title but Wilson earned the top seed because of its point differential in the two games between the teams. Both will await the outcome of today's first-round games between Anacostia (15-7)-Dunbar (11-13) at 3 and Woodson (19-4)-Ballou (10-10) at 6:30. Semifinal games will be played at Coolidge Tuesday with the finals Wednesday.