There is a type of 4-bet that I enjoy quite a bit, which you can take a look at here in Hold’em Manager (Figure 49).
4-bet semi-bluffing is much like 3-bet semi-bluffing. You just have to be more careful with the move because there are two people to deal with now. It works well these days because people become concerned when you look as if you do not mind getting flatted when you cold 4-bet. They can’t fathom you’d do this with a hand below your flatting range that flops well, such as suited gappers. They generally flat, miss the flop, and fold.
The types of people you’re looking to use this move against are prolific openers. The first person to enter the pot must be constantly raise/folding, so he needs to be opening a good deal of garbage. His RFI statistic should be north of 35%. It also helps if his fold to 3-bet is 50% or higher. South of that indicates someone who gets really touchy when they’re raised.
The 3-better should be someone you expect to be paying attention to how often the initial player is opening. He should generally have a 3-bet of 12% or more. It helps if you can identify from his positional statistics that he particularly likes to 3-bet the position he’s in. Then, he needs to be fairly predictable on the flop. Look for 60%+ folding on a street you can reach with your chip total.
Many people I introduce this play to say they’ve never seen it. This is good news. The fact that no one does it, that they rely on 4-bet bluffing or 4-bet value betting solely, means they’re not defending enough. Your 3-bet semi-bluffs are defended by the fact no one does this.
In a more meta-game stance it is worth 4-bet semi-bluffing occasionally, even if the situation isn’t perfect for it. If we’re deeper stacked and we’re disciplined postflop it can send the message that players ahead of us cannot 3-bet isolate the weaker players. They will know for the remainder of the tournament that they cannot rely on you giving them the floor to exercise their game.