A friendly spirit prevailed as Moscow School No. 20 won an interscholastic chess match against Lakeside School here, played via telex Saturday, by a score of 4.5 to 0.5. The first-board game was not completed.

This was the first time that a high school chess match was conducted by telex between Soviet and American schools. It was part of a continuing cultural exchange program between the two sister schools. The telex transmissions went from Lakeside to the U.S. Embassy, from which they were relayed by phone to the Moscow school.

The match, involving six players on each team, was the result of several months of planning.

Moves were transmitted in International Correspondence Chess Federation (ICCF) notation using numbers of four digits to record each move. Standard algebraic notation is not appropriate for international play because it employs letters to refer to the pieces. In different languages, the same chess piece is designated by words beginning with different letters. ICCF notation assigns to each of the 64 squares a number; 3546, for example, means the piece on Square 35 moves to or captures the piece on Square 46.

Derek Edmonds, Washington state's highest-rated scholastic player, played the first board for Lakeside against Oleg Skvortsov. Edmonds has an excellent chance of winning the uncompleted game. Because it was already after 1 a.m. in Moscow by the middle of the game, a proposal that the game be continued by correspondence was quickly accepted.

A swimming meet last November, also conducted by telex, was won by Lakeside.

Robert A. Karch, who coordinates the activities of the International Correspondence Chess Federation in the United States, refereed the American play.

The sister-school relationship has been promoted by Jim Talbot, a trustee of Lakeside School who operates Marine Resources, a joint fishing enterprise located in Moscow. Marine Resources provided people to operate the telex and paid for the match.