Poker hand in blackjack (former croupier looking to create a new casino game)

[gcav]

Hi all, first time posting so hope I'm in the right place. I'm a former croupier looking to create a new casino game and was hoping for a little help.
Basically I need to know the actual odds for the following hands, using 5 cards from 6 standard decks.
Pair
2 pair
3 of a kind
Straight
Flush
Full house
Four of a kind
Straight flush
Five of a kind
Five of a kind suited

I think these are the right order from lowest to highest, but I may be wrong. I appreciate any help, thanks.

 

[mmm4444bot]

I ought to stay off this board, but let's see what happens with my fading memory.

If you have a single deck of 52 cards (no wild cards, no burn cards), what's the probability of getting two of a kind on the second card dealt? It's 3/51 because there are three possible cards to match the first, out of the 51 cards remaining.

Likewise, the probability of getting two of a kind on the third card dealt is 6/50 because there are three possible cards to match the first and three more to match the second, out of the 50 cards remaining.

Following this pattern, the probability of getting two of a kind with five cards dealt is:

3/51 + 6/50 + 9/49 + 12/48 = 0.6125

Note that the numerators are multiples of 3, and the denominators count down from 51.

If there were two decks instead, that's 7 possible cards for each match, and there are 103 cards remaining after the first card is dealt. In other words, the numerators are now multiples of 7, and the denominators count down from 103.

7/103 + 14/102 + 21/101 + 28/100 = 0.6931

One deck: 61.25% chance of getting two of a kind

Two decks: 69.31% chance of getting two of a kind

That's the basic idea.

I would expect that somebody on the Internet has worked out the poker hand probabilities for multiple decks. You searched already, yes?