relevant link imo http://www.flopturnriver.com/pokerfo...ng-178446.html . my understanding is that semi-bluffing is betting/raising with a hand that is rarely best on the given street, but has a chance of improving to the best hand on later streets. your equity when called is like a safety net, to use a terrible analogy, making it easier to show a profit with your essential bluff (because you never expect to have the best hand when you MAKE the bet) because some percent of the time when you are called you make the best hand, extract money on further streets etc etc. semi-bluffing also helps disguise hands and make you harder to read. this is only a basic understanding of semi-bluffing typed out by a complete fish. but it's a start if you don't understand the concept as yet.