The tap bet is a tool every poker player should have in their bag of tricks. The situation doesn’t come up that often, but when it does, it can be well worth doing.
The basic idea is to bet the right amount to “tap” a player to make him go allin. The right amount is just under 1/2 their total stack. I consider this to be more of a psychological play than anything, because it lets them think their shove might make you fold.
Here’s an example from a recent tournament. Keep in mind that we are looking at the preflop action. (The board runout in this hand was a little bizzare)
https://www.replaypoker.com/hand/replay/429287410
The target here was the BB. Since the other 2 players limped, it was unlikely either of them had a very strong hand. I expected both of them to fold, but betting just under half of the BBs stack, I retained the option to reraise if I needed to. Had I just bet enough to set the BB in, it makes it harder for him to call.
When one of the other players called, it put me in another interesting situation. When I moved in there, 2 things could have happened; either he calls or folds.
If he folds, it isolates me against the BB and adds dead money to the pot. This is a good thing.
If he calls, I really only have to beat him and not the BB. If I beat his hand but lose to the BB, I pay off the BB with the other guy’s chips and pocket the change as profit. I was in pretty good shape against anything but KK or AA, and more or less a coin flip vs AK, and his passive line made these hands unlikely.
Anyway, tap bets are worth knowing about. The right situations don’t come along that often, but when they do, tapping can be a nice way to drag a few more chips to your pile.