TO THIS CHESS LOVER, PLAYING THE KNIGHT ISN'T JUST HORSING AROUND

In the 11th game of the 1972 world chess championships, Boris Spassky trapped Bobby Fischer's queen by making an unexpected move with one of his knights. The knight, the most exquisite piece in our most exquisite game, is frequently the key to memorable stratagems, and the chess world should have paused that day in mute tribute.

Why praise the doughty horse? Because there's nothing like it on the board. Uniquely, the knight can vault over other pieces; with every leap it must land on a different-colored square, another oddity. Its L-shaped journey, two squares straight and one to the side—or is it one straight and one diagonal?—is the game's only nonlinear move. And the knight alone among chess pieces attacks the queen without exposing itself to capture. "The knight introduces an element of trickery—the ability of a David to attack the Goliath-queen—without being demolished by the larger piece," wrote Anthony Saidy and Norman Lessing in The World of Chess.

Even so, the knight is little praised and much scorned. Grudgingly, it's considered a useful piece in the opening, but less so as the game progresses. Overall, it's rated about even with the awkward bishop, which moves diagonally on one color. Says Wray McCalester, membership director of the United States Chess Federation, "The knight's better in a crowded board because it can jump over pieces, but the bishop's more useful in the end game because it's more mobile. Besides, you can't force a mate with two knights, but you can with two bishops."

In The Amazing Adventure of Dan the Pawn, an otherwise exemplary chess primer for children, the horse is pictured as an arrogant and foul-smelling brute. "Knights always think they fool the enemy by pretending to go one way and then suddenly changing directions and going another—two squares here, then one square there," says the king's pawn, Ernie. "But there's no surprise, as they do it every time."

What we have here is a case of spite. People don't like the knight because they've been burned by it. "Every grandmaster has fallen into a knight fork at some time," says McCalester. Let experts debate the relative merits of the knight and bishop in championship play; for the great majority of us, the knight's a better piece to have in hand, a critical one to eliminate from the opponent's arsenal. "Weaker players have more trouble defending against the knight than the bishop," says Shelby Lyman, the host of televised world chess championships. And more fun attacking with it. Most games among average players are really decided before the middle; at that stage the knight has usually done more damage than the bishop.

And no piece is more central to chess lore than the knight. It has been the only constant piece throughout the game's history. There was a horse on the board when chess originated in sixth-century India under the name chaturanga. "The horse moved in the Sanskrit game precisely as the knight does in modern chess," Henry A. Davidson wrote in A Short History of Chess. "Throughout thirteen centuries this move has never varied. It is so peculiar to chess that it serves as a shibboleth by which one may determine whether a board game is, or is not, a descendant of chaturanga."

The knight was always called the horse back when chess was played as a simulation of war. When medieval Europeans began viewing the pieces as a king's court, the horse became associated with a horseman—knight. How entwined were the piece and the era? Chess was actually designated as one of the seven knightly accomplishments.

Napoleon was a terrible player who attacked with his knights; a world-class cheater, he supposedly used his horses to knock down enemy pieces instead of leaping over them. Nonetheless, Josephine's lady-in-waiting, Madame de Rémusat, beat him at will.

The knight has been honored in poetry; its movements have been the basis for numerous mathematical investigations. So mysterious and treacherous are its ways that a number of chess players, frustrated again and again by it, have abandoned the game forever. Wiser players, however, cherish the piece. "A horse! A horse!" they plead. "My kingdom for a horse!"