I have always wondered this also. Years ago, I remember something like this.
Doubles: 2 people on one team (They could either shoot until they miss or rotate each time the cue ball is hit). I guess like "partners".
Scotch Doubles: 2 people on one team and they MUST rotate each time the cue ball is struck. I remember bowling in scotch doubles years ago with other guys. (One would throw the first ball and then the second guy would throw-every strike caused the other player to throw the first ball).
Scotch Dutch Doubles: Same as above except the partners MUST be a man and a woman. Dutch meaning mixed gender.
Usually shortened to just Scotch Doubles. I am curious how this one turn out. I have been asked about it over the years.
Mark Griffin