accessing
refineOptionIntervals
	| endings |
	endings := self options collect: [:opt | opt chance ].
	endings doWithIndex: [:end :i | 
		 
			(i = 1) 
			ifTrue: [(self options at: i) chance: (1 to: end)]
			ifFalse: [
				(self options at: i) chance: (((endings at: (i-1)) + 1) to: (endings at: i))
			]

	].