Out

In poker, an out is any undealt card that will turn a losing or drawing hand into a winning one. Counting outs accurately is the first step in deciding whether a Call is mathematically justified, because the number of outs feeds directly into your equity and Pot Odds. The standard counts are worth memorising. A flush draw has 9 outs: there are 13 cards of each suit and you can already see 4 of them (two in your hand, two on the board). An open-ended straight draw has 8 outs, the four cards at each end. A gutshot, or inside straight draw, has only 4 outs because just one rank completes it. To convert outs into a rough win probability, use the rule of 4 and 2. On the flop, with two cards still to come, multiply your outs by 4; on the turn, with one card to come, multiply by 2. A flush draw on the flop is therefore about 9 x 4 = 36% to complete by the river, and roughly 9 x 2 = 18% on the turn alone. The exact figures are 35% and 19.6%, so the shortcut is close enough for the table. A common mistake is counting tainted outs: cards that complete your draw but hand an opponent an even better one. If a card that makes your straight also completes a likely flush, it is not a clean out. Discount such cards, or you will overestimate your equity and call when you should fold. Treat the rule of 4 and 2 as an approximation, not a guarantee.