The Crystal's are extremely rigged, it avoids giving you good characters, especially when you calculated the normal speed stop. For an examples, the first is that it would go to its normal speed and doesn't effect it if it's a 2 star crystal, but if there's a crystal that has a chance to get a 3 or 4 star character out of it, it will try its absolute best to get the lowest possible such as its slow stopping but I keep rolling until it stops to a 2 star