Does anyone know how old 9 ball really is? I've always assumed that 15 ball rotation came first and 9 ball came later as an abbreviated version but I really don't know. The earliest I've heard it referenced was in Mosconi's book Willies Game, where he mentions as a teenager he was spotting some rich guy in 9 ball, so that must have been around 1930 or 1931 but I'm sure it's older than that.