Open-Ended Straight Draw (OESD): 8 Outs, 31.5% by River

Open-Ended Straight Draw (OESD): Definition, 8 Outs, Odds, How to Play

An OESD is a straight draw with 8 outs. Either end of the four connected cards completes the straight, putting you at about 17% to hit on the next card and 31.5% by the river.

Open-ended straight draw (OESD): quick definition

An open-ended straight draw (also called an outside or double-ended straight draw) is when you have four cards to a straight and can complete it by hitting either end. It is one specific shape of straight draw, and most of the time it has 8 outs.

Quick odds (rule of thumb):

With 8 outs, you’ll hit about 17% on the next card and about 31.5% by the river.

Open-ended straight draw illustration showing four connected cards and the idea of 8 outs — An OESD is four to a straight that can complete on either end — a clean 8-out draw before discounting.

Why an OESD is usually 8 outs

Because there are two ranks that complete your straight, and each rank has four suits.

Example: you hold 8♠ 9♠ on a flop of 6♦ 7♥ K♣.

You can complete a straight with:

any 5 (5♣ 5♦ 5♥ 5♠)
any 10 (10♣ 10♦ 10♥ 10♠)

That’s 8 total outs.

Open-ended straight draw example showing the 8 outs from 8-9 on a 6-7-K flop — The classic OESD has two ranks that complete the straight, giving eight outs before blockers or dirty outs matter.

OESD odds (turn / by river)

Exact-ish shortcut: Rule of 2 and 4

On the flop: outs × 4 ≈ % to hit by the river
On the turn: outs × 2 ≈ % to hit on the river

So for an OESD (8 outs):

Flop: 8 × 4 = 32% (very close to the true ~31.5%)
Turn: 8 × 2 = 16% (close to ~17%)

Optional exact note: with one card to come on the river, the exact chance is 8/46 ≈ 17.4%. The shortcut above is the rule of 2 and 4.

OESD vs gutshot (what’s the difference?)

A gutshot (inside straight draw) usually has 4 outs.

So compared to a gutshot, an OESD:

hits more often
gives you more semi-bluff opportunities
tends to be easier to continue with (especially in position)

Comparison of an open-ended straight draw versus a gutshot straight draw — An OESD doubles a gutshot's outs because two ranks complete the straight, not one.

How to play an open-ended straight draw

There isn’t one “always do this” rule — here are the practical defaults.

1) In position: calling is easier

When you’re in position, you get to see what your opponent does first on later streets, which helps you realize your equity.

2) Semi-bluff when fold equity exists

If you can win the pot now or hit your straight later, betting or raising can be better than calling. That is the standard semi-bluff idea.

3) Watch for dirty outs

Some straight outs are dirty.

Example: you’re drawing to a straight, but the card that completes your straight also completes a flush on the board — you can hit and still lose.

4) Use pot odds (not hope)

Pot odds tell you whether a call is profitable.

Worked examples

Example 1 (classic OESD)

Hand: 8♠ 9♠ Flop: 6♦ 7♥ K♣

Outs: 8 (any 5 or 10)
Odds: ~17% on turn, ~31.5% by river

Example 2 (OESD with “dirty” outs risk)

Hand: 9♦ 10♣ Flop: A♣ 7♥ 8♥

You still have 8 straight outs (6s and Js), but 6♥ or J♥ might make your straight and complete a flush for your opponent.

In spots like this, treat some outs as “less than 1 out” (discount them) depending on ranges.

Open-ended straight draw example where some straight outs can also complete a flush — Some OESD outs need discounting when a straight card also completes a flush or stronger hand for the opponent.

FAQ

How many outs is an open-ended straight draw?

Usually 8 outs .

What are the odds of hitting an OESD?

Roughly:

~17% on the next card
~31.5% by the river

Is an OESD better than a flush draw?

A flush draw is usually 9 outs (slightly more), but OESDs can be more disguised and sometimes get paid more.