The semi-bluff is one of the most powerful weapons in any poker player’s arsenal. If you have a good opportunity to steal the pot by semi-bluffing, you should generally take advantage of it. But like any other move at the poker table, semi-bluffs are always most effective when executed at the right time and in the right situation. If you semi-bluff too often, your opponent will know when you have a draw. If you semi-bluff too infrequently, your opponent will know to go to the library when you bet. The key to semi-bluffing is to always mix things up and never let your betting patterns become too predictable.
Suppose you flop the flush nut and are pretty sure that the fact that your opponent did so is somehow related to the flop, whether it’s top pair or a set. In this situation, many players like to check with a semi-bluff. However, there are some problems with this style of play: First, if you always check-raise in this situation, your opponent will easily pick you. Second, if your opponent does have a hand, there’s no need to check-raise here, since there’s no way he’s going to throw away the hand, and there’s a good chance he’ll still pay you if you call the hand.