June 9, 1986

Like the city mouse lording it over the country mouse, the Mets put a somewhat transient lineup on the field today and still beat the Pittsburgh Pirates, 4-3, then left town with four victories in five games over a last-place team. It wasn't particularly neat, but it worked, and the Mets now have won 12 of their last 16 games and 37 of the 52 played this season and are wallowing in a nine-game lead in the National League's East. In fact, whatever they do seems to work. Kevin Mitchell, already a one-man-gang as a rookie, played his fourth position and batted third in the lineup for the first time, and delivered a single, double and a home run. Sid Fernandez pitched a one-hit shutout for six innings, then gave up a pinch-hit three-run home run to Mike Diaz in the seventh, leading to his departure.

The election process for Civil Court judges in New York City amounts to little more than the appointment of judges by powerful county Democratic leaders, according to a report to be released today by a nonpartisan court-monitoring group. The organization, the Fund for Modern Courts, found that Democrats won 83 of 85 elections for Civil Court judgeships in the city in the last five years, and only four elections during that time could be termed serious contests with Republicans. The 108-page report, which analyzed the elections borough by borough, called the Democratic primary the ''real contest.'' But it found that in only 24 of 85 elections were Democratic primaries held, resulting in no real choice for voters in more than 70 percent of the elections.

As the American economy enters the second half of its fourth straight year of growth, economists and leading business executives find conditions sounder than they have been in two decades or more and see signs of further growth right through next year. People see great distress, depressions even, in the farm belt and the oil patch of Texas and across much of the West's mining and timber country. They note a lot of weak manufacturing businesses, an unemployment rate that remains above 7 percent and record high levels of consumer debt. But many executives and economists speak of the best underlying conditions they have seen since before the Vietnam War. No Bottlenecks in Sight Behind their optimism are the abating traumas of high interest rates, inflation and oil prices and the dollar's strength as well as prospects that the nation will soon have seen the worst of the great deficits in the Federal budget and in foreign trade.

With Larry Bird at his best and with their capacity home-court crowd in a game-long frenzy, the Boston Celtics won their 16th National Basketball Association championship today. Bird was everywhere in the 114-97 rout of the Houston Rockets that gave the Celtics the four-of-seven-game series, four games to two. In playing all but two minutes, Bird was the pulse of the offense and was in the middle of the double- and triple-teaming defense that slowed the young Rockets, upset their rhythm and forced them into 11 first-quarter turnovers. In the final quarter, he even did the work of the officials, pulling down the tangled net before going to the free-throw line.

Students and teachers in Westport, Conn., have two additional days in school this year, while 700 teachers in Irvington, N.J., are enjoying pay rises that got them up to the state's new $18,500 minimum salary. High school seniors in Long Island City, Queens, who are bilingual have been enlisted to teach foreign languages to sixth graders, and primary school students in Westfield, N.J., are now spending all their time on ''basic'' skills rather than probability, statistics and more esoteric topics. ''We tried to cut out all the extra junk,'' explained David J. Rock, the district director of instruction. The Effects of Change Such are the subtle, and in some cases not so subtle, ways in which the much-heralded school measures of recent years designed to improve the quality of a public school education are beginning to alter the lives of students, teachers and administrators in the New York metropolitan area. Students at all grade levels in New York, New Jersey and Connecticut are spending more time in school, taking more standardized tests and focusing a higher percentage of their efforts on reading, writing, math and other core academic subjects because of actions by the state legislatures and boards of education.