River Play

In this instalment, we shall examine two river decisions. The first is a synthetic example. The second is a hand I played this morning while getting myself into the Spin & Go zone in order to write this article.

Example 1 – Bluff Catching the River

We have called the BU’s min-raise in the BB and the board has run out: K4472. Having called his flop and turn bets with 76 we face a pot sized shove. The pot on the river is 300 and Villain puts us all-in for our last 300 chips.

There are two main ways of analysing this situation. Firstly, we can discuss, in theory against a balanced opponent, whether or not our hand makes a good bluff catcher. Secondly, we can decide in practice whether or not the population is unbalanced and if we should do something other than the ‘standard’ theoretical play.

In Theory

Theoretically, if we are bluff-catching we are trying to defend a large enough part of our range that Villain cannot profit from bluffing. This is a different thing from actually trying to make his bluffs losing plays and we would only seek to do that if we thought that he was bluffing too frequently (overbluffing). Villain is risking one unit to win one unit (making a pot-sized bet) and so his required success rate in order to break even with a bluff is 50%. This is how often we should seek to call the river, in game theory.

The next question we should ask is: is our hand in the top 50% of the range we make it to the river with. This question is not just to ask what are the strongest 50% of our hands in absolute terms, but what are the most profitable hands to call. The answer to this question is all about card removal. We want Villain to show up with that busted flush draw. When we hold spades, we are reducing the frequency that he holds that part of his range. Therefore, any hand with either two spades or two hearts is naturally a lower EV bluff catcher; all else being equal. On the other end of the scale we do not want Villain to hold his value range and so having a T, a J, a Q or an A will do a good job of removing some of the typical value-betting strong top pair hands. This will improve our EV when we call.

Shuffling blue poker chips

We can call the first part about not blocking draws avoidance of negative blockers. We can call the second part about blocking big top pair hands having positive blockers.

With this in mind, how should we view our 76 on K4472? In terms of negative blockers, we unfortunately have two spades, making Villain less likely to hold a busted flush draw. On the plus side, we also block K7 and 77. Overall, it would be much better to hold a K, which would significantly reduce Villain’s top pair hands; and if we really had to call with a 7, we could use a combination that did not block flush draws so heavily. In theory, this hand is a comfortable fold as it is more than halfway down our river range in terms of suitability to call. As we know, however, the game theory play is not always the right one in reality.

In Practice

In a Spin & Go, calling too wide is a common phenomenon. A newer passive player generally dislikes two things: folding and making big investments. Therefore, we should expect the population in these games to refuse to fold to our bluffs and make bluffs more rarely themselves. Unless we have a read that Villain is very aggressive; for example, we’ve seen him attack a pot already with air, raise every hand, or perhaps raise second pair on the flop, then we should assume we are facing a player who does not bluff often enough for an all-in bet on the river.

This means that we might want to fold here with some of the hands our theoretical approach told us to call 76 then, is an even clearer fold in the exploitative model than it was in the theoretical model.

Example 2 – When the River is Horrible

Earlier on today I decided to get myself into the Spin & Go mindset by playing a quick session. Interesting post-flop spots are not very common in this format with all the money flying around pre-flop, but early on in one tournament, the following spot came up:

I limped in the SB with 96 after the BU folded. The BB appeared to be your typical passive Spin & Go recreational player, limping into pots, letting people see free flops, and generally using the check and call buttons more than the bet and fold ones. Villain predictably checked, and the flop came Q109. I think my hand is a clear theoretical check/call, but against someone placid, making a min-bet for thin value and a little bit of equity denial is also quite reasonable.

I opted to check and when Villain bet half pot I reluctantly called. It’s not that I expect to have great equity here against this player, but I am getting 3-1 pot odds and a few decent things can happen. I can turn a 6 or a 9 and there will be a reasonable degree of implied odds for me on these turns because while Villain isn’t the type of player to bet with nothing on the flop, he is the type to pay me off with something on these turn cards. Secondly, I do not need to have the best hand often at all for this price and if Villain was making a cheap stab at the pot with Jx or Kx etc. then I don’t expect to be blown off of my pair later in the hand unless he improves.

The turn brings the 9 and I led out. My play here is exploitative and intuitive. Checking allows a potentially sticky opponent to escape a street of pot building with marginal hands like Tx and Jx. Leading is by far the most reliable way to make money from these very likely and abundant parts of his range. Do not be put off by thinking of donking out here as ‘fishy’ or ‘non-standard’; it should be the most profitable way to proceed.

I lead for 60 into a pot of 80 and Villain calls. The river is the J. I have a problem. Villain’s range has just made quite a few straights that obviously beat me. Does this mean I should check?

No, absolutely not. There is a much stronger line available. Villain also happens to hold a lot of one pair and two pair now that I beat. If I check, I will likely get no more value from them. Secondly, if I check I will have to fold to a reasonable bet-size against this opponent as there is too small a chance that he feels the need to bet a mediocre holding rather than taking a free showdown. While this is likely okay, I get no more value and I end up occasionally folding the best hand when he bets for some reason with a pair such as ‘I’ll represent the straight’.

I opt for what is known as a ‘block bet’. I make it 50 into the pot of 200. This is a size that our passive opponent will often call with one pair and two pair hands, almost never raise without a king, and generally play face-up against. It is the only real bet-size that allows us to bet for value with such a weak relative holding as trips on this run-out.


This hand is purely exploitative and is a far cry from the theoretical river discussion we had about bluff catching in Example 1. We shall finish of this course now with a look at some heads-up pre-flop play in the later stages of the tournament with a smaller quantity of big blinds.