The Three-bet (or 3bet) strategy is one of the most important basics in poker because most fofo the money you will earn will likely come from big 3betted pots.
What does a 3bet is?
Technically speaking, a preflop 3bet is a play where someone re-raises against a raise during the preflop action.
E.g. The player of the BTN raises to 3 big blinds and the players on the BB re-raises (3bets) up to 11 big blinds. It can either made for value or in bluff.
A 3bet might occur in the postflop phase, when a player bets, a player raises and the first one (or another involved in the hand) re-re-raise. As you can see, postflop it takes one more step to have a 3bet.
E.g. BTN makes a continuation bet, BB raises and BTN 3bets; this situation often leads to major pots.
As seen above, you can decide to 3bet for value or in bluff. Depending on the situation, the range might be very wide and both the strengths of the hands and the styles of the players involved are important factors.
3bet for value
3betting for value is by far easier to apply and understand. If you have a premium hand preflop or a very strong hand postflop like a set (questions on set mining strategy? Check here!), you want to get the more chips in the pot possibile, as soon as possible. Making a short not full list, you likely want to 3bet for value with hands like QQ+, AK preflop or twopairs, sets, major draws with many outs, postflop.
3betting in bluff
3betting in bluff is very tricky but undercovers a lot of money pretty easy to take. It requires to know well your opponents and their styles but could be insanely productive. If for instance the player on the BTN is very aggressive preflop and raises a lot to steal the blinds, 3betting him both for value and in bluff is surely a good idea, as long as you know he doesn’t like to call and play postflop.
Short list of hands interesting to 3bet in bluff with: midsuited connectors like 89s, 76s, A2-A5s.
Dangerous hands to 3bet with / to call a 3bet with
Be careful with 3bets pots because you either want to be involved in them either with strong or clearly weak hands. Let’s see an incredibly common mistake many players do and costs a lot of money:
The player on the BTN is tight aggressive and raises up to 3BB. You 3bet on the big blind up to 11BB and he calls. You hold QJ and the flop hits J93. You clearly have a nice hand but not a super strong hand you want to play the stack for; the pot is already pretty big, though, and it might be hard to fold your top pair, despite there are no guarantees it’s the best hand in the spot (your opponent might easily have AJ or KJ).
As you might have understood, if we reverse the hand and you are the one who decides to call with a 3bet with QJ, you might find yourself in a hand where you are dominated by KQ or AJ on a flop like J93 and it will be hard to fold, but even harder to win money from these spots.
Mastering 3bet pots is hard because they are fairly more rare than normal raised hands, but making as less mistakes as possible in these situation will make you save tons of money and extract value when the situations favor you.