That doesn't seem right. Suppose we use a 3-card deck {A,T,2}. The probability of getting a blackjack is 1/3. Now suppose we use two decks {A,A,T,T,2,2}. After dealing out three cards with a neutral count we could have {A,A,2}, or {T,T,2} in addition to {A,T,2}. Then the probability of a...