Playing flush boards

It came up in a hand review thread that there should be a thread to discuss how to play monotone boards. This is what I got. I find that this is hard to put into practice, but maybe just by writing it all down it will help me to play these situations better.

Never tell me the odds!

  • The odds of being dealt suited hole cards are roughly 1 in 4: your first card being whatever suit it is, the second having a 1 in 4 chance of matching the first. Actually, it’s slightly worse than 1-in-4, since one of the possible cards of that suit is already spoken for, being in your hand already. But 1-in-4 is close enough.
  • The odds of a player’s suited hand aligning to a suited board (either 4 to a flush or flopped flush) is therefore about 1/4 * the odds of the board flopping two to any suit, or monochrome to any suit. (Again, since two of the cards of the desired suit are already in your hand, and thus spoken for, the odds will be slightly diminished from this approximate amount.)
  • The odds of a player who is 4-flush on the flop filling by the river is about 35%.

Another way to think of it then, is that the odds that a 2-tone flop will give you flush problems by the river is about 35% * 25% * 25%, or about 2% if you’re heads-up vs. one opponent. This agrees with the fact that suited vs. unsuited hands are only about 2.5% stronger.

Against multiple opponents, this 2% chance increases with each additional hand at the table. Each one will have that same 2% chance of being on a draw.

One thing to think about, the above is merely the random odds, against any two random cards. We know that poker players tend to play hands selectively, folding weaker hands and playing more desirable hands. Players tend to play suited hands more often than non-suited hands, so we should probably adjust these numbers by the human bias to play suited hands and fold non-suited hands. This varies by player, so I can’t give an exact amount of weight, but it is certainly non-zero.

It’s worth keeping in mind, too, that weaker players will often make the mistake of playing any suited hand (often from any position), while stronger players will tend to fold out some of their suited hands, keeping only their suited Aces, Kings, some Queens, and connectors only.

If you can work out your opponent’s range, you should be able to figure out the percentage of that range that is suited, and thus you will know the bias factor. I leave this as an activity for the reader.

Thinking about how flushy boards play out, I think we can classify these hands into a few broad categories, as follows:

First thing to ask is: are we multi-way, or are we heads up? Multiway, flush possibilities multiply. Put enough players on the hand, and the odds are good that someone will have at least a flush draw.


In multi-way pots, it’s more likely someone has hit a flush or is drawing to it. Accordingly you should proceed with caution if you’re not at least drawing to a strong flush yourself.

If you’ve hit the flush, you can safely call most of the time, or check-raise, watching out for paired boards.

Keep in mind that a lot of boards will be two-tone, eg two of one suit, and thus four-flush for a suited player matching the board. Two-tone flops are is very common, and being four-flush is therefore not all that uncommon either. (See “Never tell me the odds!” above.)

This means that suited players who match the dominant suit of the flop will be drawing to a flush, and if they’re out there, they’re going to fill it about 35% of the time.

This means to make it -EV for them to continue the hand, if you’ve hit for a pair, you’ll want to bet big enough that their pot odds are worse than 35%.

Unfortunately this means paying off all the two pair and set hands who are already crushing you. Maybe just take up macrame instead. You can probably check/fold to most bets with even a strong top pair, and maybe check-call smaller bets.

Once in a while, such as in late position against a heads-up opponent who checks to you, you might want to try semi-bluffing top pair, but keep in mind if you get called, it’s probably by a hand that either is already beating you, or is on a draw to beat you 35% of the time.

So how often should you be betting top pair when checked to? And how should you size that bet? Well, the sizing should make it difficult for your opponent to know your hand strength. They may not know what hand you’re holding, but they will know what hand they’re on, and if it’s a flush, or a draw to a good flush, they’re going to call you or raise you. Now you can fold, satisfied that you tested the strength of your top pair. Good job, you just cost yourself extra chips and made the flush pay off. Or you can just fold it. Or you can check it, and risk them running a bluff at you the next turn. Whatever. Pairs suck on flush boards when you’re not drawing to the flush yourself.


HU, it’s a lot less likely that your solitary opponent has the flush than against multiple opponents. You can sometimes bluff these hands, and probably should some portion of the time, even with air if your opponent checks to you. You may want to defend with your top pair, two pair, sets, and pocket overpairs, particularly if you also have a draw to the flush to go along with them.

Your hand’s strength:

Flopped flush

  • A flopped nut flush can play more passively and let opponents try to catch up to something made but worse than the nut flush that they might be willing to bet. If the action on the table has been pretty wild, you might only just need to call. If the table has been especially tight/passive, you might not get any calls or bets into you no matter what you do.

  • Position. In early position you will want to check-raise more, or bet weak to induce raises that you can then re-raise. Weaker flushes should sometimes bet bigger in order to close the hand, preventing being outdrawn by players hoping to connect to fill a bigger flush. But often players will not fold high flush draws, and if they hit, they hit. You can punish them when they miss by making it expensive to call, but this comes at the expense of paying them off when they do fill.

Flopped flush draw

  • Nut draw vs. near nut draw vs. non-nut draw
  • suited draws vs unsuited draws

If you’re suited, you’re drawing to a flush when at least one card hits your suit on the flop, and backdoor draws aside, it’s really only a draw if you’re you’ve got four cards to the flush at the flop, and just need one to fill it.

If you’ve only got one card of the board color, then you can only hit if the board is four-flush to your suit. These are only decent opportunities if you happen to hold the Ace; sometimes a lone King can be good when you make a flush, but you’ll be filling the flush last, after suited hands (if any) have already made theirs. So you want to make sure if you’re playing an unsuited hand that you’re at least drawing to make a better flush than any previously-made flushes that can be out there.

Strong made hand on a flush flop

  • Sets: Sets can’t draw to the flush; the two cards in your hand are not of the suit that’s flushing on the board. You can draw to quads and boats though.

  • Two pair: You’re also drawing to a full house, which is great, but two pair hits full houses much less often than sets do. So maybe not so great. But at least you’ve got four outs in the deck. Possibly some of those outs might even be counterfeit flush fillers for your opponent. It’s great when you improve to a full house while your opponent improves to the nut flush with the same card. When that happens, it’s all but certainly going to be a big pot.

  • Keep in mind, too that not all two pair hands are created equal. There’s three ways to make two pair:
    Pocket pair with a board pair; One hole card pairing the board, plus a board pair; and each hole card pairing with the board. Usually, if you’ve paired each of your hole cards, your hand is more disguised, stronger, and doesn’t help your opponents who might have used a board pair to fill a set into a boat. On the other hand, a pair on the board will signal danger to players sitting on flushes and flush draws, so can slow the action more than a concealed, “one of each” two pair made with both of your hole cards.

  • Pocket overpairs. Depending on whether the pocket pair is drawing to the flush, you can continue with these hands, or fold them. If you made a set or two pair with a pocket overpair, see the bullet points above for playing sets and two pair. If your pocket pair is not drawing to the flush, treat it like Top pair, below, but keep in mind it could be a bluff catcher if your flush-drawing opponent misses their draw.

  • Top pair: usually safe to fold, unless you happen to be drawing to the flush in addition to holding top pair, then these are pretty good hands to play. You’ve got some showdown value from your top pair, plus the nut advantage from the flush draw (especially if your draw is to the nut flush).

Four-flush boards vs. 3-flush boards

Obviously, flushes are less common on boards with 3 suited cards than on boards with 4 suited cards. When the board is 3-flush early (solid flop, or three to the flush on the Turn) your suited cards have hit their flush, and the draws are likely to call.

Strong flush draws are more likely to sustain larger bets than weaker flush draws, for obvious reasons. Stronger draws are draws holding the Ace, and especially suited Aces. Lesser draws are pretty much everything else. K-high and Q-high flushes win too, of course, and even a 6-high flush can be a winner, but you’ll see weaker flushes checking, betting smaller, and usually calling smaller.

Weak flushes are usually strongest when they fill late, because the stronger draws may have folded, and single-card draws will have missed if there’s only 3 to the flush on the board at the river. Weak single cards filling with a 4-card flush board are almost not worth playing, for how likely it is that another player will happen to have a higher flush made with the board and one random card in their hole

Flush boards

Once in a great while you’ll see a board flush, all 5 community cards are of the same suit. This can be great if you have card that improves the board flush. Generally you should never bluff or call board flushes if someone puts in a big bet, it’s probably because they have a better-than-board flush. Usually you do not chop unless both players check, and then neither has a card that improves the flush.


This is very comprehensive about all possible flush situations. When playing a heads up pot on a monotone (flush) flop specifically, I think it’s important to consider the range and nut advantage on this particular board. It’s important to think about spots in terms of range versus range rather than exact hands or worry about always facing the nuts. I think discrepancies in perceived ranges led to some of the disagreement in the other thread.

Let’s take the example of a 6max UTG open, BB flat, 150bbs deep. The flop comes Tc6c2c. The UTG player should have a nut advantage and range advantage on this board because they can have lots of strong flushes like any Ax of clubs, K8+ of clubs, top set, as well as overpairs with a big club like JJ-AA, and even hands that miss like AK/AQ/AJ can have lots of equity with a big club. The BB on the other hand should be 3betting most hands that would flop the nuts (AK/AQ/A5/A4 of clubs and potentially AJ/A3/KQ/QJ of clubs as well), so the only nuttish hands they can have are like A7-AT of clubs or Kx of clubs. At the same time they can have lots of smaller flushes (eg 97 or Q4 of clubs), probably more total combos than UTG, and they are more likely to have middle or bottom set on this board. So, they probably don’t want to go for stacks this deep when the reverse implied odds are against them and they have lots of hands that have good equity to continue if UTG keeps betting. Basically, they wouldn’t want to blast off for stacks like the player in the hand on the other thread.

However, it’s tough to look at the hand without a good inference for the players’ ranges. In 50NL maybe I’d default to the ranges presented in the previous paragraph, but on replay I’d default to a UTG open that is lets say ATs+/88+KQs/AQ+. With this range, UTG has 4 flush combos on this flop (AK/AQ/AJ/KQ) compared to 20+ in the previous range, though these hands still represent a nut advantage over BB’s capped range. However, UTG also has 24 combos of overpairs, which include combos with big clubs. These hands in particular are likely to be overvalued on replay, and some players will almost never fold an overpair even by the river.

Looking at BB’s range against a min raise, they could literally have any two cards, but let’s say they almost never 3bet, so let’s give them all suited combos apart from AK/27/28. That means they have lots of flushes. I guess the reason leading a set is bad is because it’s not near the top of their range due to the sheer number of flushes they can have (which are vulnerable to a 4th club hitting). That’s where my confusion in this spot comes in because they can potentially get paid by overpairs or AT, while UTG rarely has a made flush, but at the same time they prevent UTG from bluffing with club draws and are betting a hand that isn’t close to the top of their range (though there are decent but not great odds of improving to a boat).


Here’s a rather interesting hand on a flush flop board that went down a couple of minutes ago.

Table history:

6-seat 1k/2k ring, I sit in with 250k, and manage to win a couple pots pretty quickly into it. I’m up around 340k, when the tone of the table seems to change, as two players opposite the table from me start taking ridiculous, huge raises, opening to 20k-70k, even 100k a few times here and there, and also jamming and open shoving.

It’s nonsense and I don’t like it. I don’t want to play against multiple splashy players, I want to play a careful strategy based on good judgement, not wild aggression and huge bluffing. I could just get up and leave, but I get stubborn and decide to try to beat these guys.

I try to hold on to my winnings, but whenever I make my standard open raise, I get blown off it by a 4-5x 3-bet that I’m not really looking to call. Some others at the table do, and some huge hands go down.

Eventually, I’ve bled from my peak of around 340k down to around 300k, when I get dealt AK, and open it a bit larger than my usual open, 9k. I get re-raised to 25k, flat, and flop nothing, table runs out check-check to river, and Splashy McBigBluff lays in a pretty large bet at the river. I don’t have anything but AK for the bluff catcher, and feel like I should call, he’s probably only betting because I haven’t showed any interest in the pot since calling the raise; turns out he’s got 33, flopped a set of 3s, and slow-played it. Well done.

I’ve dropped about 70k or so on the hand, and have dropped down to under my starting stack of 250k, so I decide to reload to the max, 400k.

A couple of hands before this hand I’m about to show goes down, a newcomer to the table – the player I ended up beating, Bud04, – open shoved pocket 55s and got called by the splashy player at the table, 10sChamp, who held pocket 88s, and the board ran out quad 55s. So, yeah, a pretty wild table.

So I’m sitting on my 400k stack, and I’m not playing anything until I get something premium, and thankfully it doesn’t take long before I get AK again.


AsKc in the SB. Everyone limps around to me, I open to 25k, UTG folds, the next two players call, including one of the two big splashers, Button folds.


4dKd2d, a solid diamond suited flop. I have top pair and no diamonds. I do not like this flop one bit. But with the way this table is playing, I can’t play like I’m scared of the flush possibilities on this board; I have top pair, I’m playing it aggressively.

First to act, I donk out a continuation bet, overbetting the pot from 78.5k to 100k. I really want to get folds from these two, and if I happened to run into two diamonds, then so be it, I’ll give them my stack if I have to, but I’m not backing down. What I expect is, perhaps one will fold, but one is definitely going to re-raise if they have any diamond. There’s four cards between the two of them and four suits, therefore it’s pretty likely at least one of them has a diamond.

So when the raise comes, I’m not surprised. The first player to act after me wastes no time, and instantly shoves. The splashy player behind them folds. I consider my action, but I didn’t just put in 125k to let it go that easily, if he’s got a flush, fine, if he’s going to make a flush, fine, but he’s going to have to beat my top pair to get this pot. I call.

V flops up… Ace of diamonds, 8 of hearts. The nut flush draw. Could be worse.

Since I have no diamond, any diamond is the nut flush draw as far as I’m concerned. So it doesn’t bother me that it’s the Ad I’m up against. I just need to dodge any more diamonds.

It’s all in at the flop, so we’re going to have a roller coaster ride to the river.

Board runs out 3c, Ac. Very briefly, I forget that I have the Ace to go with my King, and think that V has rivered me by pairing his Ace, but then the pot slides over my way, and I realize I’ve won the hand with top two pair.

Here’s the hand: Hand #718931512 · Replay Poker

This is very much not a good way to play this hand, under most normal circumstances, against more sane opponents, but it worked out for me, thankfully, this one time.

I can only defend the play I made by saying that by reading the table, I felt a looser style of play with this hand could work out. I wasn’t willing to believe V had a made flush on the flop, was very lucky to be right about that, and if he’s drawing to it, me winning this pot 65% of the time when he misses didn’t seem too bad to me. It ends up being my biggest pot of the night.

Admittedly, if he happened to have flopped a set, though, it would have been bad news for me.

Making this play, even with the best top pair, top kicker, this way, is insanely high risk, but also high reward.

Another hand I won with top pair, no draw, on a flush flop board:

I’m playing KQ at a 500/1k 6-seat ring table, and open to 4k from the SB. This table has been getting extremely limp heavy, and I haven’t had two face cards in a long time, or played anything past the flop in a long time, so I figure a standard open from out of position is likely to raise some eyebrows and may work as a blind steal.

To my surprise, it doesn’t; I get three callers. I should have raised higher.

Flop is 9sQs3s – top pair for me, but not a flop I like because it’s suited against me.

I consider that the odds one of these three players is suited spades and therefore has flopped a flush is about 1 in 16; x3 opponents, make it 19%. The odds of one of them having one spade is a lot better, though.

I decide to assume that neither of has flopped a flush, and bet my top pair. I put in a bet of about 25% pot, 4000 into 16500.

I expect good players will likely call this a questionable play, c-betting out of position into two opponents where I do not have the nut advantage, and say I should have check-called or check-folded, depending on sizing if one of the players behind me bets. And perhaps it is.

I feel at this table it’s not a bad play; these players have been very passive. By betting small here, I’m attempting to pot-control, so I don’t have to fold to a pot-size bet if someone decides that they want to bluff or bet their draw on the big side. If I do get raised, I can let this hand go, and be fairly confident that it’s the right play. I’m not expecting to get too many folds for this 25% sizing, but I am expecting to get hopefully calls from hands I can beat. I’m giving an excellent price to call for someone drawing to the flush, and they’ll miss about 65% of the time. If a 4th spade hits the board, well, it’s time to give up.

The BB calls, the UTG player folds, and the player behind him calls. Pot is now 28500.

The Turn card, 3d, pairs the board, which I think may help me out a little bit; not only do I improve to two pair, drawing to a full house, but the board pairing may put players on a flush draw on guard against a possible full house, and make them less inclined to raise. I put in another 4k bet, now it’s a tiny bet relative to pot, 14%. I’m expecting both players to call this bet, and hoping no one raises, and both do call.

The river is the 7h, and I put in a value bet of 10000 into a pot of 40000.

BB folds; I presume they were on a flush draw, no pair, made +EV calls to see if they could fill their draw, missed, and folded the river.

The remaining player calls, shows 98, no spades, good for 2nd pair, and I take down a pot of 60k.
To get called by 2nd pair here, I feel like I sized my bets well. Considering it started out at 16k preflop, it ends up being a really nice pot to win without the benefit of holding the nuts.