<P> While the modern folk game of three - ball bears no resemblance to nine - ball, the earliest - known version of three - ball was essentially nine - ball played with only three balls, racked in a triangle, in which the 3 ball was the money ball . It is a quick game, and (due to the comparatively very high possibility of pocketing the 3 ball on the break) one with a more significant luck component than nine - ball and most other pool games . </P> <P> Six - ball is essentially identical to nine - ball but with three fewer balls, and racked in a three - row triangle, with the 6 ball (or more often the 15 ball; see below) as the "money ball ", placed in the center of the back row . According to Rudolph "Minnesota Fats" Wanderone, the game arose in early 20th century billiard halls that charged by the rack instead of by the hour, as nine - ball players had already paid for the 10 through 15 balls and did not want to waste them . This explanation of the game's origin may be particularly plausible because six - ball remains popular today as a diversion or practice round among nine - ball - playing bar pool players, using coin - operated tables that deliver a full set of fifteen balls . </P> <P> Seven - ball is a similar game, the primary differences being there are only seven object balls, racked in a hexagon, and the game is won by pocketing the 7 ball . Seven - ball is rack ed with the 1 ball at the apex on the foot spot and the 7 ball (the money ball) in the center of the hexagon . This game is not particularly common, and is primarily known because of ESPN's Sudden Death Seven - ball which aired in the early 2000s . Though hardly necessary, specialized equipment for the game can be purchased, including a unique black - striped seven ball and a hexagonal rack . </P> <P> Ten - ball is a more stringent variant of the game, using ten balls (racked in a triangle with the 10 ball, the money ball in this case, in the center), in which all pocketed balls must be called and in which the money ball cannot be pocketed on the break for an instant win . Due to its more challenging nature, and the fact that there is no publicly known technique for reliably pocketing specific object balls on the break shot, there have been suggestions among the professional circuit that ten - ball should replace nine - ball as the pro game of choice, especially since the rise of the nine - ball soft break, which is still legal in most international and non-European competition . Regardless of the future of the nine - ball versus ten - ball debate, there are already hotly contested professional ten - ball tournaments . </P>

What color is the 9 ball in pool