Randomization based on equity is an important concept that you must know about. The concept is basically bluffing or semi-bluffing in spots where you have equity or turn equity but are generally bad spots to bet. Because these spots are somewhat “bad” to bet in, for example the top card on the board pairs on the turn, but you turn a flush draw, not only will you be betting this turn a relatively low amount of the time, when you do, you are more likely to get folds from other strong hands that aren’t trips because it is seen as a “bad turn to bet”. The fundamental reason why bluffing in bad spots is profitable is because you rely on having some extra pot equity with your draw/weak draw. Also, your hand is often somewhat disguised when you hit, and you will be betting these spots so infrequently your opponent will consider not raising all but the strongest hands.
To demonstrate what I mean by randomization by equity, ill show you a simple hand, We open 78s preflop, we raise and get a caller and are out of position. Flop comes down J62 rainbow, we bet the flop, the turn comes a Jack, 6 or 2, pairing the board. In this spot, its generally a bad spot to bluff and barrel the turn, but in the situations when we turn our backdoor flush draw, we choose to barrel it again. The reasons we do this are 1) We cant profitably check call with our draw, IE we have no showdown value. 2) We are betting this turn very infrequently and giving up often with most of our air hands, so should get more credit from a thinking player with a medium strength hand. 3) We have some form of equity, so that when we get called, we will make the best hand on the river and be able to value bet it. 4) A scary card could come on the river for our opponents range and we force a fold with a 3rd barrel. 5) It makes us hard to play against.
Another concept that is in the same vain is betting without a ton of equity on the turn because its a good double barrel card. For example, You have A4 of diamonds and raise preflop from the cuttoff and the big blind calls you, the flop comes down 23T. You bet and get called by the big blind, the turn comes down as a queen. In this spot, its a mandatory double barrel because the queen is much better for your overall range than his overall range, in this spot you will frequently get a fold from all pocket pairs that peeled a good looking flop, on the turn you are likely to get a call from a ten. The river becomes a close spot but you will often get a ten to fold on most rivers, especially any card 9 or higher that doesn’t give him two pair.
Basically, what im saying is the extra equity of a gutshot and an overcard, gives you more equity in the hand, just enough to make it an effective barrel spot (Wheather or not its a good barrel spot without a gutshot, or two overcards remains to be seen, I think it is, but the extra equity of having some kind of outs to the best hand makes this a mandatory barrel spot).
Also consider the same spot 23T board, you cbet and get called, turn comes a queen. In this spot you should be betting so wide, KJ, AJ, AK all become mandatory barrels, anytime you turn a flush draw or straight draw and its an overcard to the board, thats right, mandatory barrel. Against regulars who think your barrelling alot in this spot (which you are) it doesn’t really matter because the overcard usually brings you some extra equity, its really as simple as saying, you gain equity and your opponents hand range as the preflop caller, his range gets weaker. Your opponent will usually be in a spot where there middle pair is either crushed or you have two overcards and a gutshot to make the best hand, most of the time, villans will take the road of least resistance and fold instead of making a light calldown on the turn and river.
Remember, the key here is that anytime you have pot equity (IE you have a percentage of making the best hand on the river, whether it be with overcards, a flush draw, a straight draw, a gutshot) your bluff has to be less successful for it to be profitable than when you bet as a total bluff. At the end of the day, its all about equity, make sure you maximise yours.