Bowls is a British sport that is at least 800 years old. According to legend, it was famously being played on Plymouth Hoe by Francis Drake in 1588 as the Spanish Armada hove into view. The game is played on a bowling green and there are two types, depending on whether the green is flat (lawn bowls) or has a convex (crown green bowls). A small white ball called the "jack" is rolled across the green and the objective of each player is to roll their "wood", a larger ball with a weight bias, towards the jack with the round being won by the player whose wood ends up closest to the jack. Several rounds are played until, for example, one player (or team) accumulates 21 points (one point per round). Games can be contested by singles or doubles and competitive matches are between teams representing rival clubs. The international governing body is World Bowls, based in Edinburgh, with 54 affiliated national authorities.