Desirability Index (blackjack)
A term coined by Don Schlesinger in his book Blackjack Attack.
It is a number derived by dividing the win rate by the standard
deviation for the particular game being examined and multiplying
the result by 100. The lowest desirability index number given
in Schlesinger's book is - 0.52 and the highest is 16.04. The
higher the number, the better the game. In general terms, a
player would look for a desirability index of 6.6 or higher
to find game which would be considered to be playable to most
counters.