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04-10-2002, 10:32 PM
This is purely a theoretical question. Please excuse the long-windedness of this post.


In poker, the more improbable hand is ranked higher than those more probable. For example, it is less likely to be dealt a four of a kind than a full house in 5 card stud. So, full houses lose to a four of a kind.


Now, my question. In N-card stud, how are the probabilities of the hands affected, and at what values of N are the probability crossovers and for what hand ranks? I am assuming that straights and flushes are still based on 5 cards, and you must play your best 5 card hand.


For example, at N = 2, a pair is less likely than nothing, and so the hand ranks still hold. A Royal Flush is better than a four of a kind... a pair is better than a high card. (Note that even though Royal Flush all the way down to three of a kind have equal likelihood at N = 2 (Zero probability), we are consistent, and no crossover has taken place).


At N = 11, a high card is MUCH less likely than a pair. The only way this can happen is if you have A234 6789 JQK. Any other 11 cards give you at least a pair or higher.


So the question is at which values of N are the crossovers, and how does the probability-based hand rankings change as N approaches 52. At N = 52, we are once again consistent with our 5-card stud probability-based rankings system with Royal Flush having probability = 1, and everything else equal to zero (recall that we are ALWAYS going to choose the best 5 card hand according to the traditional poker rankings). This is consistent, since we are only concerned with crossovers, and there is no crossover at N = 52 compared to our usual N = 5 case.


Any ideas?

04-11-2002, 05:12 AM
in 7cs, there are more one pair hands than no pair hands.


brad

04-15-2002, 09:56 AM
The time it would take to either solve these situations by hand, or the computer time it would take to brute force solve this, isn't worth the reward, in my opinion.


I can offer one tiny data point from the bridge world: 64.92% of 13-card hands have at least a flush. (Bridge distribution tables show that 21.551% of hands are 4432, 10.536% of hands are 4333, and 2.993% of hands are 4441, and those are the only ways to not have a flush.)