Dart Board Measurements:
Standard height from the floor to the bullseye on the dartboard is 5 feet 8 inches, while the oche (distance between the front of the board and the toeline) should measure 7 feet 9.25inches.

Basic Rules:
In a game of 501 the object is for one player or a team to be the first to reach zero from starting total of 501.

In simple terms, after three darts are thrown, the throwing player subtracts the total scored from his current total until he reaches zero.

In order to reach zero each player must finish by throwing a double i.e. if player one has 36 remaining he must hit double 18 to win, while if player two has 45 remaining he must hit single 5, double 20 to win - or a another combination of scores provided the final dart scores on a double.

Some versions of the game require a 'double start' whereby players must begin the game with a double as well as 'checking out' on a double. The World Grand Prix uses the 'double in, double out' rule.

Games can be played to a 'Best of' format whereby a player or team winning three legs in a 'Best of Five Leg' competition wins the match.