Bowling pins are arranged in a triangle, and knocking down all ten earns a strike.

The longer version

Ten pins are racked in a triangular formation with the head pin at the front, and clearing all of them with the first ball of a frame is a strike. The triangle matters because pins knock into each other: the ball rarely touches more than a few, and most falls come from pins scattering into other pins.

That chain reaction is why entry angle is studied so carefully, since a ball arriving slightly off-centre can still take every pin if the deflection pattern works. A strike scores more than ten because the next two balls count as a bonus. Pin spacing and weight are specified, and the setting machinery must place them within tight tolerances.

Where this entry sits

Facts here look at the rules, equipment and odd histories behind familiar sports and games, from balls and rackets to cards, boards and playing fields. Expect small details about scoring quirks, stadium design and the long story of the Olympic Games. The full list sits on the Sports and Games page, where every entry is listed in order.