When you play on 99x first main point to know about your bets, and must do a preroll before hit 99d
99x its hard for me
when hunting payout 99x the first thing I will do is rotate seed.
then I use preroll according to the feeling at the time, I often use 50-200 prerolls.
then use bb and setting number of roll 99. if it's still not hit I also increase 2x bb per 99 roll.
this way works for me