You've got a good hand but there is a possible flush draw on the board, or even worse a possible flush. What do you do? Okay, you know you should bet, but how much? Too little and you'll get calls from players who have hands besides just flush outs. Too much and you'll scare everybody away, leaving the pot rather bare. There is no easy answer, but we can try to see what happens in a few situations.

The setup

A flush draw board occurs when the flop is showing two suited cards. It is not possible for any player to have made a flush yet. A player with a matching suited pocket will have the flush draw. That player may or may not have another hand - while this may be hard to ascertain it is a rather vital part of betting into a flush draw. This article concerns itself mainly with what the player holding the likely best hand does when there is a flush draw on the board.

Depending on the community cards the best hand may be top pair top kicker, or it could be two pair and the occasional set. Knowing what hands are possible on the flop is important in order to decide whether to bet. It's not just a matter of knowing how to deal with the suited cards. A straight, set, or even two pair could end up dominating the hand. Betting has to be a subtle balancing act.

For example, a player holding J♠ 7♦ on a flop of K♥ 9♥ J♣ shouldn't really be worrying about a flush. They have a bigger problem of the king and possible straights on the board. Assuming they can win with the jack is a mistake. In contrast, a player holding K♦ T♦ on a flop of K♣ 9♣ 3♦ has good reason to believe they are holding the best hand. They are in a good position to hook a flush draw player.

Don't Needlessly scare them away

When a flush draw is possible many players have a tendency to chase away other players and secure the pot immediately. This may be a safe way to play, but it throws away a good opportunity to pad the pot. Consider that if a flush draw has only a 35% of completing by the river, that means 65% of the time the flush won't show up. Those certainly sound like good odds to collect some calls!

An anxious player will make a large bet and scare away the flush draw. How much really depends on the opponent. Some tight players with a flush draw will strictly calculate their pot odds at 19% for the turn so even a half-pot bet could scare them away. Other players are banking on implied odds or maybe they've incorrectly considered their pot odds at 35%, so even a pot sized bet might not rattle them.

The fear in allowing people to chase is actually a fear of playing the turn and river incorrectly. Many players feel so uncertain of what to do if another matching suit comes up that they would rather just not see any card at all. Consider first however that the matching suit is only going to show up 35% of the time. There is no point in letting the that fear take over your game.

The value of the chase

Such calculations can never be perfect since opponents can be unpredictable. Occasionally they will hit a strong hand that isn't a flush. There will always be some unanticipated risk involved, but as stated before, making plays out of fear is not a good option.

All other factors barred, consider a 65% chance of winning the hand. This comes from the fact that the person with the flush draw has a 35% of making the flush by the river. This is actually split into two steps however, the turn and the river. There is a 19% they will get the flush on the turn, and then a 20% chance on the river. Each of these two streets will have their own betting.

If a bet of $100 is made on the flop, and called by a flush draw, there will be $200 in the pot. The flush will be completed by showdown 35% of the time, so there is on average a $35 loss in this bet. On top of this there's a bet on the turn, say $100 again. This $100 has a 20% chance of being lost to a flush, so another $20. The flush chasing player will likely fold any bet on the river if the flush isn't made, so no further value need be considered.

Pay attention to an underlying point being made here. If the turn or river does show the card which completes a flush draw the betting situation changes completely. Simply putting in another bet and/or calling a bet may have negative expected value. There has to be a really good reason to distrust a player who has been representing a flush draw should the draw come up.