Outs
The remaining cards that improve your hand
Definition
Outs are the unseen cards that improve your hand enough to likely win the pot. Counting your outs is poker's first mathematical reflex: it turns an intuition ("I have a draw") into a usable number for deciding whether to call, raise or fold. The classic counts: a flush draw on the flop has 9 outs (13 cards of the suit, minus your 2, minus those on the board), an open-ended straight draw has 8, a gutshot has 4, and improving a pair to a set offers only 2. Watch out for "dirty" outs: a card that completes your straight but also the opponent's flush isn't worth a full out. To convert outs into a probability, the rule of 4 and 2 gives an excellent approximation: multiply your outs by 4 with two cards to come (flop to river), by 2 for a single card. A flush draw on the flop is therefore worth about 9 × 4 = 36% (exact value: ~35%), and 9 × 2 = 18% for the turn alone (~19% exact). Combined with pot odds, this estimate is enough to make correct decisions in real time.
You hold 9♥8♥ on a 7♥6♠2♥ flop: flush draw (9 outs) + open-ended straight draw (8 outs, 2 of which are already counted in the flush) = 15 clean outs. Rule of 4: ~60% to get there by the river (~54% exact). Your "drawing" hand is actually a favorite against a pair of aces.
Frequently asked questions
How do you count outs without making mistakes?
Count the cards that genuinely give you the best hand, then remove two categories: duplicates (a card completing both your flush and your straight counts once) and tainted outs, the ones that improve your opponent even more — hitting your straight on the very card that brings a third card of one suit, for instance.
Is the rule of 2 and 4 reliable?
It gives a good ballpark: outs × 2 for one card to come, × 4 for two. The × 2 is close to exact (9 outs → 18% quoted against 19% real). The × 4 already overstates from about 7-8 outs and then drifts fast: 15 outs are quoted at 60% against a real 54%, and it only applies if you truly see both cards — so mostly all-in.