Enphetamy The concept is chancification continues onwards to infinity.
Before when 10 was when the 100% guaranteed loss, my suggestion was:
0-10 - 10% chance/castle to get a castle
11-20 - 1 castle on victory PLUS 10% chance per castle above 10 to get 2
21-30 - 2 castles on victory PLUS 10% chance per castle above 20 to get 3
etc.
That removes the 19/29 castle plateaus, as there is very little incentive to stay there.
Now with chancification starting at 6 for 100%, may have to finagle the first 6 castles so its just 100% castle loss from 6-10, then the extra chancification kicks in. Or something.
Say chancification 10 times fast.