A poker player is drawing if they have a hand that is incomplete and needs further cards to become valuable.
For example, in seven-card stud, if four of a player's first five cards are all spades, but the hand is otherwise weak, they are drawing to a flush.
In contrast, a made hand already has value and does not necessarily need to draw to win.
Not only draws benefit from additional cards; many made hands can be improved by catching an out – and may have to in order to win.
An unseen card that would improve a drawing hand to a likely winner is an out.
A flush draw has nine outs (thirteen cards of the suit less the four already in the hand).
An inside straight draw has four outs (four cards to fill the missing internal rank).
There are a multitude of potential situations where one hand needs to improve to beat another, but the expected value of most drawing plays can be calculated by counting outs, computing the probability of winning, and comparing the probability of winning to the pot odds.
of catching two outs with two cards to come is: For example, if after the flop in Texas hold 'em, a player has a backdoor flush draw (e.g., three spades), the probability of catching two outs on the turn and river is (10 ÷ 47) × (9 ÷ 46) = 4.16 percent.