The number of possible unique chess games is much greater than the number of electrons in the universe. The number of electrons is estimated to be about 10^79, while the number of unique chess games is 10^120.

The longest chess game theoretically possible is 5,949 moves.

The longest time for a Castling move to take place was the match game between Bobotsor vs. Irkov in 1966: 46. 0-0.

As late as 1561, Castling was two moves. You had to play R-KB1 on one move and K-KN1 on the next move.

The word “Checkmate” in Chess comes from the Persian phrase “Shah Mat,” which means “the King is dead.”

The Police raided a Chess Tournament in Cleveland in 1973, arrested the Tournament director and confiscated the Chess sets on charges of allowing gambling (cash prizes to winners) and possession of gambling devices (the Chess sets).

The number of possibilities of a Knight’s tour is over 122 million.

The longest official chess game lasted 269 moves (I. Nikolic – Arsovic, Belgrade 1989) and ended in a draw.

From the starting position, there are eight different ways to Mate in two moves and 355 different ways to Mate in three moves.

The "new" Pawn move, advancing two squares on its first move instead of one, was first introduced in Spain in 1280.

In 1985, the Soviet player Garry Kasparov became the youngest World Chess Champion ever at the age of 22 years and 210 days.

The Guiness World Record for the "Largest Chess Set" was set by the Medicine Hat Chess Club on the 27th of May, 2009.  The record stands to this day.

The first mechanical Chess Clock was invented by Thomas Wilson in 1883. Prior to that, Sandglasses were used. Sandglasses were first used in London in 1862. The present day push-button Clock was first perfected by Veenhoff in 1900.

The most commonly held belief is that chess originated in India, where it was called Chaturanga, which appears to have been invented in the 6th century AD. Although this is commonly believed, it is thought that Persians created a more modern version of the game after the Indians.