An inside straight draw, or simply an inside straight, is a hand with four cards to a straight and is missing the middle card to complete the hand.
It’s one of the worst drawing hands in terms of outs, as it can only be completed with four cards, unlike a more favorable open-ended straight draw. It’s also called a gutshot straight.
For example, let’s say that you have a 4h3s, and the flop is 6s 7c 10s. In this case, you have an inside straight draw since any 5 in a deck will give you a straight. If you are facing a big bet, you usually do not even have the right odds for calling and might be forced to fold this hand.