Straight Draw Odds — OESD vs Gutshot Explained
Straight draws come in two main varieties in Texas Hold'em: open-ended straight draws (OESD) with 8 outs, and gutshot (inside) straight draws with 4 outs. The difference in outs translates directly into a 2x difference in completion probability, which fundamentally changes how you should play each type.
Straight Draw Probability Table
| Draw Type | Outs | Flop → Turn | Turn → River | Flop → River |
|---|---|---|---|---|
| Open-Ended (OESD) | 8 | 17.0% | 17.4% | 31.5% |
| Gutshot (Inside) | 4 | 8.5% | 8.7% | 16.5% |
| Double Gutshot | 8 | 17.0% | 17.4% | 31.5% |
Open-Ended Straight Draws (8 Outs)
An open-ended straight draw occurs when you hold four consecutive cards and need one on either end to complete the straight. For example, holding 8-9 on a 6-7-K board gives you an OESD — any 5 or any 10 completes your straight, providing 8 outs total.
With 31.5% completion probability from flop to river, an OESD is a powerful draw. On the flop, you are roughly a 2-to-1 underdog to complete, which means you can profitably call most half-pot and smaller bets. Even a pot-sized bet on the flop is close to a break-even call when you factor in implied odds.
Gutshot Straight Draws (4 Outs)
A gutshot or inside straight draw needs one specific card rank to fill a gap in the middle of four cards. For example, holding J-10 on a 7-8-K board needs a 9 to complete the straight. With only 4 outs, a gutshot completes about 16.5% from flop to river.
Gutshots are generally too weak to chase with pure pot odds. At 8.5% per card, you need roughly 11-to-1 pot odds to justify a call — only achievable against very small bets. The primary value of gutshots comes from implied odds and their deceptive nature. When a gutshot completes, opponents often fail to see the straight and pay off large bets.
Double Gutshot — The Hidden Monster
A double gutshot draw has the same 8 outs as an OESD but needs one of two inner cards rather than cards on the ends. For example, holding 9-J on a 7-8-10 board can make a straight with either a 6 (making 6-7-8-9-10) or a Q (making 8-9-10-J-Q). Double gutshots play identically to OESDs mathematically but are harder for opponents to detect, giving them excellent implied odds.
Combo Draws — When Straight and Flush Meet
The most powerful draws combine a straight draw with a flush draw. An OESD with a flush draw has up to 15 outs (8 straight outs + 9 flush outs minus 2 overlap), giving roughly 54% equity from flop to river. These combo draws are actually favored against most made hands and should usually be played aggressively — raising or check-raising rather than passively calling.
Decision Framework for Straight Draws
| Situation | OESD (8 outs) | Gutshot (4 outs) |
|---|---|---|
| Facing 25% pot bet | Easy call | Marginal call |
| Facing 50% pot bet | Call (with implied odds) | Fold usually |
| Facing 75% pot bet | Marginal call | Fold |
| Facing pot-sized bet | Fold on pure odds | Fold |
| With flush draw backup | Call or raise | Call |
Frequently Asked Questions
What is the difference between an open-ended and gutshot straight draw?
An open-ended straight draw (OESD) can be completed by cards on either end, giving you 8 outs. A gutshot (inside) straight draw needs one specific rank to fill the gap, giving you only 4 outs.
What are the odds of hitting an open-ended straight draw?
An OESD hits approximately 17.0% of the time on the turn (8 outs × 2) and 31.5% from flop to river (8 outs × 4). These are strong enough odds to call many bets.
Should you ever chase a gutshot?
Only when the pot odds are very favorable (facing a small bet) or when implied odds are massive (deep stacks, opponent likely to pay off a big bet). A gutshot at 8.5% per card needs roughly 11-to-1 pot odds to call.