I have always done three balls on SS games. EMs depend on the game; Astro, El Dorado and Top card were set for five balls as there were progressive goals the player was shooting for and setting to 3 balls felt off as the game makes adjustments for it. Astro for instance starts with a couple of the "Star Trek" letters lit in 3 ball mode which makes the game feel weird. Jungle Queen and Target Alpha on the other hand get set for 3 balls as they are pretty much point based objectives that reset after every ball and waiting for a four player Jungle Queen game set to 5 balls is a little much.