What Is an Open-Ended Straight Draw?

An open-ended straight draw is four consecutive cards that can complete at either end. Hold 8♥7♥ on a 9♠6♣2♦ flop and any five or any ten makes your straight, which gives you eight outs and roughly 32% equity by the river with two cards to come. Players call it an open-ender, and it is one of the strongest semi-bluffing hands in no-limit hold'em.

How an open-ender plays out

You call a 3bb open from the CO with 8♥7♥ and the flop comes 9♠6♣2♦. You have no pair, yet you are barely an underdog against an overpair like Q♦Q♣ — eight cards get you there, and checking twice with the intention of folding throws that value away.

The reason to raise is that you win two ways. Your opponent folds now, or he calls and you hit one of your eight outs. A pure bluff needs the fold to work every time; an open-ender only needs it to work sometimes, because the hands that call you still lose the pot to you about a third of the time.

Counting the outs

Count only the cards that finish the straight. On 9♠6♣2♦ holding 8♥7♥ there are four fives and four tens, so eight outs. A gutshot has one end open and four outs, which is why the two draws deserve very different treatment.

Draw	Outs	Equity from flop to river	Equity turn to river
Gutshot	4	~17%	~9%
Open-ended	8	~32%	~17%
Open-ended plus flush draw	15	~54%	~33%

Multiply your outs by four on the flop and by two on the turn. Eight outs becomes 32% with two cards to come and 16% with one — close enough to the real numbers to bet on.

How to play it well

Three principles cover almost every open-ender you will hold.

• Bet and raise rather than call. A draw that can win the pot without improving is worth far more than one that only wins at showdown. Firing $30 into a $45 pot with eight outs is profitable long before the river arrives.
• Discount dirty outs. On 9♠6♠2♠ your straight card also brings a flush home for someone else. Those are partial outs, not clean ones, and treating them as full outs is how stacks disappear.
• Respect the low end. With 5♦4♦ on 7♠6♣2♥ an eight completes 8-7-6-5-4, but anyone holding a nine has the bigger straight. Low-end draws win small pots and lose large ones.

Position decides how hard you can press. In position you can raise the flop, check back a blank turn and take a free card; out of position that same hand often plays better as a check-raise, because you will not get to realise your equity cheaply.

Before you commit a stack on a draw, run the hand against the range you actually face. The poker equity calculator puts your open-ender up against an overpair, a set or two overcards in seconds, and the gap between 32% and the real answer is where most of the money in these spots is won and lost.