odds question

[ZEN MASTER]

If anyone can tell me what the odds of the board in holdem double pairing is , I would sure be very thankfull.

[BruceZ]

[ QUOTE ]
If anyone can tell me what the odds of the board in holdem double pairing is , I would sure be very thankfull.

[/ QUOTE ]

5-card board, 2-pair or full house on board, but not quads:

[ C(13,2)*C(4,2)*C(4,2)*44 +
2*C(13,2)*C(4,3)*C(4,2) ] / C(52,5) = 4.9%.

1st line is for 2-pair only:
C(13,2) is the number of ways to choose ranks of 2-pair.
C(4,2) is the number of possible pairs for each rank.
44 is the number of ways to pick the unpaired card.

2nd line is for full house:
2*C(13,2) is the number of ways to choose rank of trips and pair.
C(4,3) is the number of ways to choose the 3 matching for full house.
C(4,2) is the number of ways to choose the 2 matching for full house.

C(52,5) = total number of board card combinations.