A backdoor flush refers to one in which players must hit a card during both the river and the turn, so as to better their hand. Thus, should players be holding an A4, while the flop is Q 9 6, getting a club on both the turn and the river gives players a flush.
In itself, backdoor draws are not all that useful, but can often enhance a hand enough for it to draw, especially when there are other potential outs like an overcard or a bottom pair combined with an overcard.
Limitations Of Backdoor Flush Draws
To form up a backdoor flush draw, players are first required to hit their suit during the turn and on the river. The odds of this happening is set at 23:1, which is not as good as it could be.
Also, as backdoor draws require players to hit a couple of cards, they are often obliged to wager on both the flop and the turn. This requires odds that are much better than the 23:1 being currently offered on the flop.
Let’s get into more detail on these:
Assuming that players are in a ₤1 -2 limit game, with a ₤1 wager staring them in the face during the flop, this effectively closes the betting. To complete the draw, players most probably need to call a turn bet, which makes it vital that the pot odds be carefully investigated.
Since occasional folding is likely on the turn, the average risk can be estimated, with the draw being continued roughly 20% of the time during the turn. The average total investment can be calculated as ₤1 + (0.20 x ₤2) = ₤1.40.
For a justifiable investment, a pot of around 23 x ₤1.4 is necessary, which translates to ₤32. Players should therefore only call the flop when the potential reward is a minimum of ₤32.
The chances of a pot of such munificence happening along is however extremely rare. Even when available, players risk a raise occurring behind them.
The 32:1 limit shown here can as well be applied to whatever limit players decide to use. Thus, if they choose to play from ₤10 to ₤20 in an online casino, then the pot should be worth ₤320.
Similarly, if they are betting from ₤20 to ₤40, the worth of the pot should be around ₤640 and so on. All these go to show that back-door flush draws are usually not advantageous to players, except when extra draws are available that can be added to them.
There are occasions when it is possible for a backdoor flush draw to change a fold to a call. It is also important to realize that there are a couple of different backdoor flush draws, one of which is far better than its partner. This will be illustrated below:
In case A, players can have a couple of cards of identical suit and one of these hits the flop. In this example, the card held is A 10, while the flop is K 7 3.
In case B, players have a suit in hand, with a couple of an identical suit hitting the flop. The suit being held in this example can be A 10, while the flop is K 7 3.
In the first scenario, the first example is better than the second, as the flush is hidden, were players to hit it. In most cases, players should be able to gain a good raise or even a re-raise on the river. In the second example, there are lots of potential problems, with players holding a just a single card of the suit in their possession.
The first issue with the second example is the fact that a trio of cards of identical suit awaits in the turn. Should an opponent hit a flush, this might result in quite a few raising and/or re-raising, thereby making steepening the cost of draws to the river.
Should players hit the flush, a quartet of cards of identical suits awaits on the river. Unless an extremely weak opponent is faced, this is highly likely to result in little to no action.
Such draws are also essentially valueless unless players are drawing right down to the nuts or almost.