What does Gutshot mean in poker?

A gutshot, or inside straight draw, needs one specific rank to fill a gap in the middle of a sequence, giving it only four outs. Holding 5-6-8-9, for instance, you need a 7 — and there are just four sevens in the deck. That makes it one of the weaker drawing hands in poker. Worked example: you hold 8-9 and the board is 5-6-K. The four sevens are your only outs to a straight. Using the rule of two and four, that is about 8% to hit on the next card and roughly 16% by the river with two cards to come. Compare that with an open-ended straight draw (eight outs, about 31% with two cards) or a flush draw (nine outs, about 35%): the gutshot is markedly weaker. It matters because the price has to be right. With so few outs, a gutshot rarely justifies a call on Pot Odds alone; it is usually played as a semi-bluff, or backed by extra Equity such as two overcards or a flush draw. The common mistake is chasing a bare gutshot on poor odds, hoping to spike the one card. To call profitably you generally need large implied odds — the prospect of winning a big pot when you do hit. See also Outs, Equity, the open-ended straight draw and the semi-bluff.