I found some rules online to a version of poker played with dominoes. But it was a really, really horrible version. So bad that I won't even link to it, in fact (though it is the first Google result for the term if you want to find it). And I thought, "I could do way better than that."
So I came up with a list of possible hands. But I have no idea how to calculate how probable they are, which means that I can't rank them. Additionally, the probabilities will of course change depending on the size of the set. Double-9 is the smallest set that they can all be used in, but I'm thinking double-12 (so there are 13 ranks, like in cards) would work a lot better, in spite of having 91 pieces to a poker deck's 52 cards.
Here are the basics: numbers are ranked naturally (so there is no ace equivalent that can be either high or low). Doubles are considered to be an additional rank that is higher than all the others, in some cases. Each player gets 5 dominoes which they arrange in a row, touching by the long sides, to make 2 rows of 5 numbers. Any number on either side that isn't part of a hand combination is referred to as a kicker. Kickers on a double count highest, regardless of the double's rank.
Here are the hands I've come up with, with some examples. There is some overlap between them because I don't yet know how they should be ranked. Also, plain pairs are not counted as anything special - it takes at least 3 dominoes to make something besides just "high number".
Royal Flush: a straight flush in doubles. Ranked by highest double.
Straight Flush: a sequence on one side and a 5 of a kind on the other. Ranked by the suit of the matching side, followed by the high number in the straight.
Flush: 5 of a kind on one side, or five doubles. Ranked by the suit of the matching side, followed by the highest kicker.
Double Straight: 5 in sequence on each side, not necessarily ordered. Ranked by the highest number in the higher straight, and then by the highest number in the lower straight.
Straight: 5 in sequence on one side. Ranked by the highest number in the straight, followed by the highest kicker.
Long Straight: 10 numbers in sequence over both sides.
4 of a kind: 4 of a kind on one side, or four doubles. Ranked by the suit of the set, followed by the highest kicker.
Full house: 3 of a kind on each side and the other 2 numbers are identical on both sides. Ranked by the highest triplet, followed by the second triplet. Doubles do not count as a suit for this hand. Equivalent to a double 3-loop (see below).
Double 3 of a kind: 3 of a kind on each side, or 3 doubles with the two other dominoes making another 3 of a kind with one of them. Ranked by the highest triplet, followed by the second triplet, followed by the highest kicker.
3 of a kind: 3 of a kind on one side, or 3 doubles. Ranked by the triplet, followed by the highest kicker.
Five-loop: 5 dominoes that could link to form a loop. Ranked by number of doubles included (can be up to 2), followed by the high pair, followed by the second highest pair, etc.
Four-loop: 4 dominoes that could link to form a loop. Ranked by number of doubles included (can be up to 1), followed by the high pair, followed by the second highest pair.
Three-loop: 3 dominoes that could link to form a loop. Ranked by the high pair within the loop, followed by the second pair.
Comments and suggestions are welcome!
Last edited by Jared on Fri Nov 23, 2012 12:12 pm, edited 3 times in total.