optimal time to put a 3 bet is when you are dealt a hand that is the top of your range such as 10 jj qq kk aa ak aqss even.. also if loose agro player keeps raising than you can 3 bet him alot wider due to him having bad hands.. also when ever im in the small with hands like KJss K10 A2ss to AKss i like to 3 bet these hands odut of position depending on the player who raises
I tend to 3 bet when there is the entire table limping. If it's folded to me and its blind vs blind, If it's folded to ,e and it's a relatively short stacked/tighter player next to act. If I have a premium hand I 3 bet. Lots of situations.
When I have AK AQ I tend to three bet
When I have AA will 3bet most of the time
In the first scenario I waiting for the reaction of the initial raiser if he goes over the top with a 4bet I'm likely fold knowing he's might have high pair If it's a call I'm looking to bet on the flop
In the second scenario I just trying to take the pot or eliminate the field to heads up
I say hardly ever in cash games,mostly in nl 1/3-2/5 games you hardly ever bluff and just value bet all day. A 3 bet re raise is kinda stupid in cash games because it's a zero sum winning situation. For example say you have ak suited in hearts on the button and you raised 15 bucks from 3 limpers in a 1/3 games and you get a fold and 2 callers. The flop rolls Q-5-7 two spades you get a bet of 25 bucks 1 fold and you raise it to 50-back to 100 and you go ballistic with a 175 3 bet raise putting him nearly all in.. Congrats the guy had 10-10 and got scared and folded the best hand. Problem is bad things can occur with the same flop same scenario. Next time the guy just calls your 2 bet with a set of 77 and the turns rolls q-5-7-k. He checks so you figure he must have AQ and your king is good so you bet about 75% of the pot and the guy calls you down even when the river rolls and ace and you love your 2 pair.. In a nut shell it's a break even proposition over time so it's bad in cash games and great in tournaments cause you can bet bigger and it's a tournament blind format where chips matter and not real profit margin.
I'm not saying just trap or value bet all day in cash games though sometimes you can have a set of kings and get a guy who reraises someone with a flop or turn of 10-K-9 2 clubs or a semi bluff of 89-k with him holding 10-j and your set of kings are vulnerable to 3 bet and a call might be better! The reverse can be said though no matter if he is trying to steal or inflate the pot and some will say 3-4 bet or shove to make him draw to your made hand. Sometimes though if there are open ender draws and flushes to be made your kings are 40-60 and it's a safe play to call his moderate bets and hope the board pairs to a flush and he just shoves. Other times you know your beat and you can toss em. You learn this a lot by seeing the 5 card flop in limit and it's characteristics of what does and might occur quite often.