Double barrel poker is the second attempt to take a pot away post flop. Your initial barrel would be a flop bet. Double barreling means that you are bluffing, you would not use this term if you were betting multiple streets for value. While it is a moderately advanced strategy double barreling can be effectively applied at almost all limits of the game. The proper implementation of a double barrel requires a decent amount of prior exposure to poker.
Knowing when to double barrel poker ensures the effectiveness of this technique. A double barrel is effective if, and only if, you are able to assign your opponent to a general range of hands. If you have no clue where you stand in a hand it would be a good idea to abandon the idea of a possible double barrel completely. This is what leads many players to making ineffective double barrels, they fire away without having a clue why they are betting.
Once you have a general idea of what your opponent likely has, the next step is to determine whether the majority of their range connects with the board. For example, if you had put your opponent on a range of all pocket pairs and AJ+, would it be a good idea to fire on a board of 7 4 9 A? Yes. If they called with a smaller pocket pair they will be increasingly worried about the 7, 9, and now the ace. If the turn was a 3, however, it would be much better to slow down as any hand that they called the flop with is likely to call the turn as well. While hands with an ace were in their range, most of them would have folded on the flop; because of this we can represent the ace in addition to the 7 and 9.
Pretend the board is 7 4 9 6. The fact that you have gotten to the turn increases the odds dramatically that they have a pocket pair. If they do have a pocket pair they are highly unlikely to make a fold when this turn card comes. It does not change a whole lot and would not generally instill a whole lot of fear in hands like pocket 8s. While it is entirely possible that they could have floated the flop with a hand like AQ it is much more likely that they have called with a made hand. Even if they did happen to float this flop with a random ace they might still raise a double barrel because they know that this board misses a lot of your range. It is much easier to determine that this is a bad spot to double barrel when you have already decided what range of hands you are putting them on. If you played the hand blindly you wouldn’t know whether this was a good or bad board to fire on.
You may have noticed that your hand was never even mentioned in these douexamples. This is an important aspect of double barreling poker. Your hand is not nearly as important as theirs. You have a weak hand, that is a given when double barreling, you just want them to let go of theirs. Once you’ve picked up this strategy it’s time to move onto the triple barrel strategy.