backdoor draw poker DECISION POINT: UTG min-raises Preflop and MP1 calls, the Hijack calls, and you call with 8♥9♥. The Small Blind calls and the Big Blind folds. The Flop comes Q♦6♥10♣. The Small Blind and UTG check, MP1 bets, and the Hijack calls. Action is on you, what do you do here? Oleg Granovsky To me, its very likely that they are drawing. Youre blocking value hands like AT, KT, QT, and JT that have top pair and good kicker or with a straight draw. Hands like AJ, J9 have more combos than hands containing a Ten like AT, JT. A hand like AJ has ~8 outs to hit the straight however they might also believe that hitting an ace is good which it isnt against top set. The fastest approach probably to assign a bit mask for each card rank e.g. deuce=1, three=2, four=4, five=8, six=16, seven=32, eight=64, nine=128, ten=256, jack=512, queen=1024, king=2048, ace=4096, and OR together the mask values of all the cards in the hand. Then use an 8192-element lookup table to indicate whether the hand is a straight, an open-ender, a gut-shot, or a nothing of significance one could also include the various types of backdoor straight draw without affecting execution time.