Hero Calling Strategy: When to Call or Fold on the River

In this article, we'll focus on river spots when we face a bet. First of all, what is hero calling and then what are the characteristics to consider when deciding to call or fold? When talking about hero calling, we mean a tough calling decision on the river. Either because the defending player has a very marginal hand or the aggressor showed a lot of strength during the hand.

In this section, we'll examine four factors, the first and most important being the pot odds, which determines mathematically how big part of our range we "should" call. Then, we'll discuss the betting range, which brings us closer to our decision. After that, we'll focus on blockers and discuss when they matter. Last but not least, we'll discuss exploitative ideas that could shift our idea if we should defend or pitch.

Probably the most crucial part when deciding to (hero) call is our pot odds. Ask any poker player; they'll calculate pot odds first to determine how big a chunk of their range they should call. If you don't remember how to calculate pot odds, check our detailed article here. To summarize the formula, you need to divide the bet size by the sum of the pot plus the bet you face plus your call and then multiply by 100. If you are a visual type, here is the equation for better understanding:

Pot odds = (bet size) / (pot size + bet size + call size) x 100

Let's see an example! Your opponent bets $100 on the river into a $100 pot. Using the formula makes it easy to realize that your pot odds are 33%. So your hand needs at least 33% against the Villain's perceived range to make a 0 EV call. If your hand performs better, you have a winning call; if not, that is a losing call. Note that this doesn't mean you'll always win the pot; it's just that you make a mathematically profitable decision.

Knowing the percentage and how much we should call sounds excellent, but how do we decide which hands qualify? The next thing we should examine is the betting range of Villain. Of course, we'll never be sure, but we can study GTO to determine a proper betting range.

Most of the time, our opponents will bet a polarized range, which will contain her best hands for value, balanced out with some bluffs according to the bet size they use. Our job is to determine betting thresholds. Namely: 1. Which is the worst hand she could bet for value? 2. What hands are too mediocre to bet? Aka is not strong enough to value bet but has enough showdown value not to bluff them. 3. What is the threshold for bluffing? Once you have figured out Villain's betting range, you can move to the conclusion of how your hand is performing against that perceived range.

Let's see a simplified example where your opponent bets $100 into the $100 pot, and her range is six combinations of AA and two combinations of 72o. Your hand is JJ, so let's see how your hand performs against this range. You can calculate for yourself or use an EQ calculator, which will be helpful for more complex ranges. So we'll lose 6 out of 8 times and win 2 out of 8, which is 36,2%, greater than the 33% pot odds provided by the bet size of Villain. This means we have a profitable call to make in this toy game.

The next topic we'll discuss is a very sensitive one. Beginners often misunderstand how blockers work, often overestimating their importance. We can state that the narrower the ranges are and the more polar range Villain bets, the more important blockers are.

What are blockers in poker? The basic idea is that your actual hand has a card removal effect on the range your opponent represents. The more your hand blocks from the values Villain would bet and the fewer blocks from the bluffs, the better blocker characteristic it has.

The most important spots are 3-bet, 4-bet, and single-raised pots with multiple overbetting and polarizing bets. If you face scattered aggression, such as a bet-check-bet line or any similar, the less important thing is to block the nuts, for example (since your opponent won't have those hands in that node).

Exploitative thoughts are one of the key parts of our hero calling. If we can estimate how our opponent will deviate from the optimal strategy, our river decisions will be more profitable.

You need to have an idea if your opponent is capable of bluffing or even overbluffing. If yes, all your bluffcatchers will become profitable calls; hero calling is a good idea. However, bluff catching won't be such a good idea if you face the average low-stakes regular who is usually under-bluffing.

Another thought is to examine how the board reduces the possibility of bluffs. For example, Villain should turn a pair into a bluff. Also, there might be no natural bluffs by the river due to the runout. How would you assess that situation? Do you think an average regular player can add creative bluffs, or does she mostly have it when she bets?

Disclaimer! Your exploitative ideas can be very profitable if you understand well what's going on around you, but can be very expensive if you are not. By deviating from the optimal, you also open yourself to exploitation.

In our sample hand, CO opens to 2,3bb, and we call from the BB with ♠K♠8. The flop comes ♥K♦️9♣2, and CO continues with a 1/3 c-bet (presumably with her whole range) that we call. The turn card is the ♠4, and CO puts in a hefty 125% overbet. At this point, we still have to stick to the pot, so we call once more. The river brings the 2h, and CO fires a third bullet for 150% of the pot; the action is on us to decide whether to hero call.

Let's go through the points we stated are essential. First, the pot odds are 37,5%, and we know that since the pot size went from 2,3bb open, SB folds (0,5bb), and we call on BB for 2,3bb. On the flop, Villain bets 1/3 (1,7bb) into a 5,1bb pot; adding our call gives us 8,5bb. On the turn, the 125% (10,6bb) overbet and the action leads us to a 29,7bb pot. Last but not least, on the river, we face a 150% overbet (44,5bb). By using the earlier provided formula:

Pot odds = (bet size) / (pot size + bet size + call size) x 100

PO = 44,5 / (29,7 + 44,5 + 44,5) x 100 = 37,5%

Now, let's compose a probable range for CO that could choose this line, starting with the worst hands she could bet for value. It will probably be around a top pair of good kickers like KQ or AK. Then she'll have pocket AA, sets like 44, 99, KK, and quads for pocket 22. (note that a savvy player might check hands like AA and KK on the turn to protect check-back ranges, but we'll calculate with full frequency bets this time).

Now, let's list the most apparent bluffs for CO. The board is so dry the most likely bluffs are EQ-driven and mostly gutshots like QJ, JT, A5, and A3. Having all this info about Villain's range, let's calculate how our hand performs against it.

Note that we made a somewhat exploitative assumption about Villain's range. If you compare it to the GTO solution, you can notice that the composition of the range arriving to the river lacks bluffs like 4x and total air, which would be required to reach a balanced range. That's why the bluffing part of the range is formed around these missed gutshots (which is more realistic when playing against humans), while in GTO, those hands would bluff only sometimes to avoid overbluffing. In our sample, CO massively over-bluffs; she should calculate the value combos based on the bet size (150%) provided, which gives the ratio that she could have no more bluffs than 37,5% of her range.

This is how the GTO betting and calling range would look like:

Notice that we did not consider blockers in our decision-making since the exploitative reasoning was much more important and emphatic. But if you look at the betting range, K8 seems like a fantastic hand for making profitable hero calls. There are no 8x in Villain's bluffing range, but the value part contains many Kxs. Thus, we block value and unblock bluffs at the same time. Everything is more balanced in the GTO simulation, so ♠K♠8 would be a break-even call, even blocking some bluffs.

Hero calling is a fun topic; hopefully, after reading this article, you understand it better. You'll need to consider the most essential factors and distinguish which are relevant against your opponent in that specific spot. You'll always have to calculate pot odds; without that, it's impossible to determine a calling range. Then, you need to estimate Villain's range and if you have any exploitative reason to call or fold wider. Last but not least, you could consider the blocker characteristics of your hand. However, the latter only really matters in tight-range configurations.

Good luck with sharpening your hero-calling skills!