Practical Poker Math

Odds of Runner – Runner
For runner-runner analysis, one number we need is the total
possible 2-card combinations from the remaining 45 unseen
cards:
(45 * 44) = 990
(1 * 2)
Back Door Low Draw >>> Runner-Runner Low
When playing Omaha Hi-Lo, it is often of great interest to
know the odds of making a backdoor Low.
With 2 low cards in the hole and 1 usable low card on the
board, even if the board low card is paired, there are 20 cards
of 5 ranks, any unpaired 2 of which will make the runner
Low — Comb(20, 2), minus the 30 pairs possible among the
cards from these 5 ranks. Therefore:
(20 * 19) = 190
(1 * 2)
190 – 30 = 160 possible 2-card combinations WILL make a
runner-runner Low:
Total Possibilities = 990
– WILLs = 160
WILLNOTs = 830
Odds of a Runner-Runner Low
WILLNOTs : WILLs
830 : 160
Reduce
43
Odds in Omaha Hi-Lo