Ernie Deitschel, age 14, of Hattiesburg, Miss., for his question:

WHEN DID WE START TO PLAY CHESS?

Chess is a popular game of skill between two players that involves intense intellectual competition with almost no element of chance. The game, which has been challenging many of the best minds of the world for almost 14 centuries, originated in the Indus Valley in India in the 6th century A.D.

The game was originally called Chaturanga, or the army game. It spread rapidly along the routes of commerce and conquest, first to Persia, then to the Byzantine Empire and finally throughout the rest of Asia.

The Muslim world, on the threshold of its greatest scientific and cultural accomplishments, welcomed chess with unbounded delight. The Arabs extensively studied, analyzed and wrote treatises on the game, and in the process developed the algebraic notation system.

Chess reached Europe sometime between 700 and 900, in part through the Islamic conquest of Spain, in part via marauding Vikings and, later, from Crusaders returning from the Holy Land.

In the 16th and 17th centuries the evolution of chess took a major leap forward. The queen became the most powerful piece on the board. The pawns were also permitted to advance two squares on the first move and the "en passant," or "in pasing," rule gave them even more power.

Also introduced at this time was the castling move.

Italian players began to dominate the game about this time, wresting this supremacy from the Spanish. They, in turn, were superseded by the French and English in the 18th and 19th centuries when chess, until then principally the game of royalty and the aristocracy, moved into the coffeehouses and universities. With the public now playing chess, the level of play improved considerably. Matches and tournaments were played with greater frequency.

The first international tournament, held in London in 1851, was won by a German named Adolf Anderssen. Shortly thereafter, in 1857, an American named Paul Morphy became the world champion.

Each player has 16 pieces, one set being called White and the other Black. Each set consists of a king, queen, two bishops, two knights, two rooks (or castles) and eight pawns. The game is played on a square chessboard divided into 64 alternate light (or white) and dark (or black) squares, that is always placed between the players so that the corner square to the right of each player is white.

The eight vertical rows of squares running from the front edge of the chessboard nearest one player to that nearest the other are called files. The eight horizontal rows that are at right angles are called ranks. The rows of squares extending diagonally across the board are called diagonals.

The object of the game, which symbolizes warfare, is to capture  ¬or to "checkmate"    the opposing king. The defeated king is never removed from the board, however, as are the other pieces and pawns when they are captured.

The basic rules and principles of chess are easily mastered but thsubtleties of advanced play require intensive study and concentration.