3Betting
A 3 bet is a raise to an earlier raise (ie preflop it's the 3rd bet if we include the big blind as a bet). It clearly represents a show of strength and will put your opponent to a difficult decison.Preflop 3Betting
As with all your bets, the 3bet is either for value or as a bluff. If you have a strong hand and get maximum value from it then your 3bet will build a large pot rapidly and also give you the initiative in the hand. Even if you miss the flop a continuation betIf the raiser on the previous street opens the next street with a raise, then that's a continuation bet will often show sufficient strength to fold out most of your opponents hands. Bare in mind though that it reduces your rangeThe range of hole cards that a player would be expected to play from a certain position or in a certain situation drastically for your opponent, and they can reasonably put you on a high pair such as QQ+ or AK.Since 3-bets clearly represent a strong hand it's important to mix in enough 3-bet bluffs to prevent playing your hands effectively face up. Being brave enough to put in a large 3-bet as a bluff is profitable for several reasons - firstly you'll take pots down immediately since a 3bet will make most marginal hands fold, and secondly your opponents will be more ready to call your 3bets which creates value for your value 3-bets.
Defending Blinds
The most common positions to 3bet preflop are the blinds. The reason is that it's usually to defend your blinds from a steal by the button or COCut-Off position. One place to the right of the button. They will be opening with fairly wide ranges, and will rarely be able to profitably call a 3bet. Also your range from the blinds should be very tight, and most of the hands you would play from this position are hands strong enough to 3-bet your opponent.3-bet bluffs from the blinds against an opponent who is stealingRaising with the hope that all the players left to act will fold and you win the blinds. Typically stealing is done from the button or cut-off a lot is also important. Generally your blinds are a lost cause - you are so out of position that's it rarely worth while playing from the blinds, and if the button raises generally it's best to just give it up and let him steal. If you 3-bet your strong hands plus a few bluffs however it will soon make most players think twice about robotically raising in every steal situation. Repeatedly doing this will at some point wear off though, and a button who has become aware that you are 3-betting too often will realise that most defending bets are lightRaising with a hand that's typically not strong enough to warrent that raise is referred to as raising light, and 4-bet you which you have to fold to (unless you're really lucky and he chose the moment you had AA!).
Which Hands to Bluff With
When you do decide to throw a 3-bet bluff into the mix, don't do it with any hand - you still want to leave yourself with a chance if it gets called.The best hands to bluff with are medium suited connectorscards that are sequential in number such as 76s, while the worst hands are lower broadwayA card between Ten and Ace cards (ie KQ, KJ etc) or Ax such as A7. An opponent who calls a 3bet probably has a strong hand, and hands such as KQ can easily be dominatedCards that can be beat easily by similar hands - for instance A6 may make a pair of Aces, but A7 to AK all beat it (ie K7 is dominated by many Ax hands) by their range (in other words, even if you hit the flop they probably also hit the flop but with a better hand). If your suited connector hits the flop however, it has the chance of making a monster. It also means that you won't feel tied to your hand when it misses, and even though you invested a big 3-bet into the pot it'll be a hand that's easily thrown away rather than risking the small chance you could still win.
Calling or Raising 3-Bets
Generally just fold to a 3bet. If you have a low or medium pocket pairHole cards that are paired and the 3-bet was larger than a minraise then you usually don't have the odds to see if you can make a set (set mining). High pocket pairs (JJ - QQ) and AK may be worth calling (but stay alert that you're playing a similar range to your opponent), while the premium hands such as KK and AA should be 4-bet or shoved.A lot depends on your opponent and whether you believe they are 3-bet bluffing or not. If a player is 3-betting a lot, especially from the blinds, then either calling with a wider range (ie including 99 and TT) will be for value, while 4-bet re-bluffs become effective (again, bluff with the right kind of hands like mid suited connectors).