I think 99% bets are not even allowed on most sites right?
I think you got it back to front... and they're wanting to wager 10% if there are 2 rolls in a row under 1 or above 99... then wager on the 1% chance bets... not on the 99% chance bets

ie.
Roll 1 = 0.74
Roll 2 = 0.87
Roll 3 = wager 10% of balance on chance = 1, bethigh = false (ie. bet low)
or
Roll 1 = 99.4
Roll 2 = 99.87
Roll 3 = wager 10% of balance on change = 1, bethigh = true (ie. bet high)