Boards with four cards of the same suit are a special combination of weird and rare...

...and many players misplay them as a result.

Some players tighten up big time on four flush boards, never committing a bet without the first or second highest flush.

Other players turn up the aggression on four flush boards, which is a strategy that will work well against some players while failing versus others.

The best approach is somewhere in between, and that’s the approach you’re going to learn about today. Here’s what we’ll cover:

• How a Four Flush Turn Should Impact Your Overall Strategy
• Four Flush Example: K♠️ J♠️ T♠️ 3♠️
• Bet Sizing on Four Flush Turns
  • Big Bets with Strong Flushes 
  • Small Bets with Straights, Two Pairs, and Sets

Let's get started.

How a Four Flush Turn Should Impact Your Overall Strategy

If you read the last two articles, you’re going to be familiar with the types of strategic tweaks that are required on four flush turns. To sum up the findings from Alex’s private solver:

• On all turns, our average betting frequency should be around 47%. The bet sizes used range from 25% pot to 200% pot.
• On four flush turns, our average betting frequency should be a fair bit lower. The bet sizes used are generally big (75-100% pot) with some small betting (25-33% pot) mixed in.

We can understand why we should make these adjustments by considering the incentives of individual hands in our range. 

The Incentives of Individual Hands
...in case you skipped the last article or just want a refresher.

When considering an individual hand's incentives versus your opponent's range, its helpful to separate your opponent's hands into two groups:

• Hands that will continue versus your bet or raise. The better your hand's equity is against the continuing range, the more incentivized you are to raise.
• Hands that will fold versus your bet or raise. The better your hand's equity is against the folding range, the less incentivized you are to raise.

Of course, a given hand's equities against these two groups tend to move together. For example, if you have a hand that has very strong equity versus the fold range (making it less inclined to check-raise), the hand probably also has strong equity versus the continue range. The effect of the latter cancels out the effect of the former, which makes your hand more inclined to check-raise.

Four Flush Turn Example

Suppose we raise preflop and our opponent calls in the big blind. The flop comes K♠️ J♠️ T♠️ and our opponent check-calls our c-bet. The turn is the 3♠️ and our opponent checks again. 

Let’s consider our incentives to bet if we held the 7♠️.

First, how do we do vs opponents folds? We have 100% equity because our opponent is unlikely to fold any better flushes, two pairs, or sets. In other words, versus just our opponent’s folding range, we have no incentive to bet with the 7♠️.

What about vs opponents calls? Our equity actually isn’t quite as high as our absolute hand strength might suggest. If we’re behind versus a higher flush, we have 0% equity. Even if we’re ahead of a hand like a set or two pair, there are at least a handful of rivers that make our hand second best.

We are incentivized to check with the 7♠️ on K♠️ J♠️ T♠️ 3♠️ versus both the continuing range and the folding range of our opponent. 

Here’s the point: the 7♠️ is the fifth best possible flush and a pretty strong hand relative to our range, yet it is still not strong enough to bet with for value. Therefore, we should have a pretty narrow betting range.

Bet Sizing on Four Flush Turns

Our primary bet size should be big, but not too big — betting pot is a fair option. If we bet too big (2x pot, for example), our opponent's decision is made too easy — they can simply fold almost everything but the nut flush, which they will have relatively often.

To quote Alex:

We’re gonna have more EV with our strongest hands [including the nut flush] by betting a bit smaller on both the turn and river...We’re just gonna get a ton of folds on the river when we try to go for such a big size.

So that’s why we’re not seeing huge sizes. We’re seeing something around about pot or maybe a bit bigger sometimes. In this [K♠️ J♠️ T♠️ 3♠️ board’s] case, it’s a bit less than pot.

Alex goes on to talk about a second bet size that’s used by his solver, particularly on our K-high example board: a small bet of around 32% of the pot. 

Small Bets with Straights, Sets, and Two Pairs on Four Flush Turns

The solver bets small (25-33% pot) primarily with hands like sets, two pairs, and straights at some frequency, as well as some ace-high flushes to protect the overall small betting range.

The non-flush made hands are incentivized to bet small versus our opponent’s folding range because any spade on the river would counterfeit our hand and result in a split pot. 

Two pairs and sets have some incentive to bet against our opponent’s continuing range too. They actually have equity versus our opponent’s many flushes. Betting with two pairs and sets also prevents our range from becoming capped when the board pairs on the river. (If we only bet flushes on the turn, we can never have a full house or quads when the board pairs.)

However, there’s one key thing to understand before using this small bet size on four flush boards…

You should do it less often as your opponent’s range contains more flushes. This will typically happen on lower boards, like 7♠️ 6♠️ 3♠️ 2♠️, because then your opponent can have the higher flushes like K♠️ T♦️

or Q♣️ J♠️ (both of which were not possible on K♠️ J♠️ T♠️ 3♠️). 

It’s not really too important to stress over exactly which boards we want to be betting [often] with these [marginal] hands and on which boards we don’t. 

The main things to understand here are the [concepts at play]. The fact that it’s plausible that we can have this small sizing and it’s also plausible that we won’t. And whether or not we do will depend on the flop sizing and exactly how many flushes both players have, and so on.

[You may ultimately want] to make your decision based on how your opponent plays. If you think your opponent will play particularly badly against the small size, perhaps you want to include the small size [in your strategy]. If you think your opponent will play well [against the small size]...then you [shouldn’t include it in your strategy].

Want to learn how Alex recommends playing versus small bets on four flush turns? (You know, just in case one of your opponents reads this article.)

Watch the video and skip to 13:35 for Alex’s counter-strategy versus small bets on four flush turns.

Ready for part 4? Check it out here.