[5] It is unknown how thirty-eight transitioned to the modified ruleset mandated by cowboy pool, nor the derivation of its name.
The first mention of Cowboy pool is in a 1908 rule book,[6] published about the same time that eight-ball (under a prior name) was first gaining popularity.
Beginning with ball in-hand from the kitchen – the area behind a pool table's head string – the incoming player must contact the three-ball first.
The failure to score in one of the delineated manners on any shot ends the player's inning at the table.
[7][9] The 90th point in cowboy pool must be reached exactly, and the failure to do so is a foul resulting in a loss of turn.