The standard deviation of the sample mean is 5.08/sqr(n), where n is the number of hands. The standard deviation of full pay deuces wild is 5.08. Perhaps a better question is how many hands would I have to play to have a 90% probability of getting to 100.66%? Although the more you play the closer your return will get to 100.76% about half the time it will be above and half the time it will be below. There is no number that will give you a 90% probability of attaining or exceeding that percentage. So in that situation the player should be mindful of the effect of penalty cards.' If the player had just one suited card, or any card that could be used to complete a straight, then the odds of forming a flush or straight would be depressed, lowering the overall expected return below that of discarding everything. However this is only marginally better than discarding everything. For example if the player had a suited 10 and king, with no other cards of that suit, nor a 9, jack, queen, or ace, then the player should keep the two to a royal flush. By discarding it the players odds of forming a flush are 'penalized.' Sometimes penalty cards can affect borderline plays. The discarded suited card would be called a flush penalty card because it could have been used to complete a flush. For example if the player had 3 to a royal and 4 to a flush the correct play is to keep three to the royal, discarding the fourth suited card.

However for those who must play near perfectly here is my explanation, 'A penalty card is a potentially useful discarded card. In my opinion beginning players should not use a strategy that considers penalty cards.

I just rewrote my explanation of penalty cards.

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