A roundup of the week Feb. 12-18

PRO BASKETBALL—Atlantic Division leader Washington, which had won five straight and 13 of its last 16, Host three of four. After dropping a 107-99 decision to second-place Philadelphia, the Bullets edged San Diego 138-136 in double, overtime despite a 45-point performance by the Clippers' Lloyd Free. They then lost 119-108 to Phoenix and 109-103 to Golden State. Warrior Guard Phil Smith, who had scored 20 points in 15 minutes, suffered a ruptured Achilles tendon in the second period and will be sidelined for the remainder of the season. He had started 305 consecutive games, the longest current streak in the NBA, at the time he was hurt. Washington maintained its five-game lead as Philadelphia also lost three of four. Cleveland beat the 76ers 113-100, and Central Division leader Kansas City upended them twice, 108-106 and 119-104. The Cavs also had a 127-117 win over New York, which has lost six in a row and fallen into the Atlantic cellar. Seattle snapped a four-game losing streak with a 116-104 defeat of Atlanta, then beat Phoenix 119-104 and moved back into first in the Pacific Division, two games ahead of Los Angeles, which was 0-3. Sonic Dennis Johnson pumped in a season-high 30 points against Phoenix, while the Suns' Walter Davis, who finished with seven points, failed to score in double figures for the first time in 138 regular-season games. Three San Antonio wins coupled with two Houston losses enabled the Spurs to regain sole possession of the top spot in the Central Division. The Rockets beat Portland 119-116 but were knocked off by Detroit and Indiana, which were both unbeaten. Kevin Porter, who had 19 points and 15 assists in the Pistons' 111-107 victory over Denver, finished with 20 and 19 in a 110-96 win over Houston. For the Pacers, who have won nine of their last 12, the 124-120 defeat of Houston was the second of four victories in which five players averaged in double figures.

BOATING—OBSESSION, skippered by Steve Nichols, won the fourth race of the SORC series over a 135-mile triangular course off Miami (page 44),

BOWLING—TOMMY HUDSON defeated Gary Dickinson 270-225 to win a $90,000 PBA tournament in Sterling Heights, Mich.

DOGS—CH. OAK TREE'S IRISHTOCRAT, a 4-year-old Irish water spaniel owned by Anne Snelling of Ottawa, won best-of-show at the Westminster show in Madison Square Garden. He was the first of his breed to win the top prize in the show's 103-year history.

GOLF—BRUCE LIETZKE shot a 15-under-par 265 to win the $250,000 Tucson Open by two strokes over Tom Watson, Buddy Gardner and Jim Thorpe.

Amy Alcott defeated Sandra Post on the third extra hole to win a $100,000 LPGA tournament in North Miami Beach. They finished regulation play at 285, three under par.

PRO HOCKEY—NHL: Adams Division leader Boston, which had won just four of its last 13 games before the league's break for its series with the Soviet National Team, suffered a winless week. The Rangers didn't allow the Bruins a shot on goal during the first period in a 5-1 rout, and Tom Gorence's two goals lifted Philadelphia to a 5-3 victory over Boston. Two nights later Minnesota gained a 3-3 tie with the Bruins when North Star rookie Bobby Smith scored a pair of goals in the second period. Toronto moved into a deadlock for second in the Adams with Buffalo, which had won four in a row before dropping a 6-3 decision to Pittsburgh. The Maple Leafs tied the Flyers 2-2 and beat Los Angeles 5-2 behind Walt McKechnie's hat trick. Toronto also defeated Smythe Division leader Chicago 5-2. The Black Hawks later skated to a 4-4 tie with Atlanta and, led by Ivan Boldirev's three goals and an assist, beat St. Louis 5-1 to move eight points ahead of second-place Vancouver, which was 0-2-1. The Islanders, who were 2-1 and lead the Patrick Division by 13 points, upended the Canucks 5-3 as Bob Nystrom scored twice and Denis Potvin added four assists. Unbeaten in its last 13 starts, Montreal tied Los Angeles 2-2 and defeated Washington 2-0 to maintain an 18-point lead over the second-place Kings in the Norris Division.

WHA: The Whalers lost three straight before Mark Howe's two goals and Andre Lacroix's three assists lifted them to a 4-1 win over Quebec, which has lost eight of its last nine. New England nevertheless maintained its one-point lead. Edmonton climbed from fourth to second with three wins that extended its victory streak to six games. During that string, 18-year-old Wayne Gretzky, who stands eighth in the league in scoring with 61 points, had five goals and seven assists.

HORSE RACING—SENSITIVE PRINCE ($5.80), Jacinto Vasquez up, won the $150,000 Gulfstream Park Handicap by four lengths over Jumping Hill. The 4-year-old covered the 1¼ miles in a track-record 1:59[1/5].

MOTOR SPORTS—RICHARD PETTY, driving his Olds-mobile at an average speed of 143.977 mph, won the Daytona 500 by one car length over Darrell Waltrip, also in an Oldsmobile (page 18).

TENNIS—ROSCOE TANNER defeated Brian Gottfried 6-4, 6-2 to win a $250,000 Grand Prix tournament in Rancho Mirage, Calif.

Chris Evert beat Martina Navratilova 6-3, 6-4 in the finals of the $150,000 Avon Championships of Los Angeles.

TRACK & FIELD—EAMONN COGHLAN of Ireland broke the world indoor record for the mile at the San Diego Invitational. His time of 3:52.6 was 2.3 seconds faster than the mark Dick Buerkle set in 1978 (page 16).

Gennadiy Valyukevich of the U.S.S.R. broke the world indoor record for the triple jump at the Soviet indoor championships in Minsk. His leap of 56'8¾" was 5½ inches better than the mark set by Victor Saneyev of the U.S.S.R. in 1976.

MILEPOSTS—FIRED: Coach LARRY COSTELLO, 47, of the Chicago Bulls, who are in last place in the NBA's Midwest Division. Assistant Coach SCOTTY ROBERTSON, 49, was named as an interim replacement.

HIRED: As football coach at Mississippi State, EMORY BELLARD, 51, who had a 6½-year record of 48-25 at Texas A&M before resigning in the middle of last season.

TRADED: By the New York Knicks, BOB McADOO, 27, three-time NBA scoring champion who is averaging 26.9 points this season, to the Boston Celtics for three 1979 first-round draft picks and reserve Center TOM BARKER, 23.

DIED: BENJAMIN H. TICKNOR, 70, two-time All-America center (1929-30) at Harvard who was known as the Great Defender; of cancer; in Peterborough, N.H. He was elected to the College Football Hall of Fame in 1954.

Tony Plansky, 78, three-time national decathlon champion (1925, 1926, 1928), NFL scoring leader in 1929 and Eastern League batting champion (.376) in 1930; of cancer; in North Adams, Mass. Plansky coached the Williams College track and cross-country teams from 1931 to 1978 and was elected to the Helms Track and Field Hall of Fame in 1967.