When poker players play regular stud, there are no older children and 2, 3, 4, 5, 6, 7, so there are 28 cards in a * * * *.

So draw five cards from 28 cards.

C (5 5,28) = 28 * 27 * 26 * 25 * 24/(1* 2 * 3 * 4 * 5) = 98,280 cases.

(Here, c (5,28) is used to indicate the number of combinations of 5 starting from 28. )

As for the straight flush, there are only four suits (8, 9, 10, j, Q) (9, 10, j, q, K)( 10, j, q, k, a), 3× 4 =/kloc.

So the probability is12/98280 =1/8190.

If it is an irregular 52-card stud, there will be * * *.

C (5 5,52) = 52 * 51* 50 * 49 * 48/(1* 2 * 3 * 4 * 5) = 2,598,960 cases.

Straight flush, there are four colors (a, 2, 3, 4, 5) to (10, j, q, k, A)-* * 10× 4 = 40 cases.

So the probability is12/2598960 =1/216580.