I’ve been spending a lot of coaching time recently working with HoldemResources Calculator, and guiding my students through a variety of preflop scenarios designed to give an accurate perspective on the ways in which we can adapt to our opponents’ tendencies throughout an MTT, particularly when it comes to preflop opening ranges. I’ve observed a particular tendency among a lot of players which I think is perhaps a fairly significant leak for some of them – they tend to over-compensate for one specific possibility that they’re particularly worried about.
It could be that they’re concerned that there’s a very good reg directly to their left, who they’re worried will outplay them in postflop scenarios; it could be that there’s a particularly aggressive player with a high 3-betting frequency behind them; it could be a shortstack who’s in a good position to shove over a raise; or it could simply be that there are several particularly passive, weaker players who don’t like to fold preflop, so they’re wary of getting into awkward postflop spots by opening weak hands. Regardless of the specific details of the spot, I think it’s important to maintain a realistic perspective on the adaptations we make, and avoid over-adapting to the point of missing out on good spots.
Considering your opponents’ options
In many spots, the options our opponents have once we open a pot preflop are significantly limited by their stack sizes. For example, we may consider when trying to establish our opening range in a given spot, that any reasonably competent player in the small blind with a stack of 14 big blinds is reduced to either shoving over our raise, or folding. Similarly, we may expand this consideration to the point where we assume that any player with less than perhaps 20 big blinds is unlikely to flat-call an open-raise, unless they’re in the big blind. This places limitations on the possible scenarios we actually have to worry about, which makes our decision of what range to open a lot simpler.
If we believe, based on the stack sizes of the opponents left to act behind us, that we’re very unlikely to ever get flat-called and have to play postflop, then the only aspects in which our starting hand actually matters are in order to establish our raise-calling or raise-4-betting ranges, and to identify the impact of blockers on our opponents’ 3betting frequencies. Conversely, if we’re playing very deep-stacked and all the opponents behind us have the option to flat-call our raise and play postflop if they so desire, then we should be very careful about opening hands that play poorly postflop, and we should consider that the value of any blockers in our hand is most likely greatly diminished, if not completely outweighed in the event that such a hand presents us with difficult postflop scenarios.
Thus, our opening ranges (and therefore opening frequencies) should be heavily dependent upon the options available to the opponents left to act behind us – when expanding our opening ranges at deeper stacks, we should veer in the direction of including more playable, suited or connected hands, while at shorter effective stacks we should forego hands without blockers and start opening those which reduce our opponents’ 3-betting frequencies.
Don’t fixate on one opponent
This is a common error made by many players. When faced with a particularly aggressive opponent left behind, they tend to tighten up their opening range significantly, in order to avoid being put in a difficult situation by this opponent’s 3-bets. This is a valid concern to some extent, but there are several possible adaptations that can be made to our opening ranges, calling ranges versus a 3-bet, and our 4-betting ranges that can help us to negate this possibility, and it is important to remember that the more players there are left to act behind us, the less significant it is for one opponent to play differently than the others.
If we’re in the small blind, for example, it obviously makes a huge difference how the big blind plays – indeed, it’s the only thing that should really dictate how we approach the spot, since it’s guaranteed to be a heads-up hand. On the other hand, if we’re under the gun, we have eight players left to act behind us, and the impact of each individual player’s tendencies on the cumulative frequencies of the table is always going to be minimal.
Let’s say we decide to raise under the gun at a full-ring table with an unknown hand. What’s the frequency everyone folds? Well, if we arbitrarily say that each player left to act behind us is either calling or 3-betting with the top 10% of hands, then their folding frequency is 90% in each case, or 0.9. By doing a calculation of 0.9 to the power of eight (since there are eight players left to act behind us), we can see that the cumulative folding frequency of the table is 0.43046721.
If we posit the scenario that one of these players is extremely aggressive (or passive – it doesn’t matter, since we’re just calculating folding frequencies) and increase that 10% to 30%, then the cumulative folding frequency goes down to 0.33480783 – a 10% decrease. One player playing three times as many hands as the others only led to a 10% change in how often our raise gets through unchallenged.
The concept in action
Let’s construct a scenario for analysis. Imagine we’re playing at a five-handed table, and everyone is 50 big blinds deep. We’re under the gun, and we have to decide what range to open. I’ve run this scenario through HoldemResources Calculator, and at an open-raise size of 2.5 big blinds (appropriate for these effective stacks), our opening range at the Nash equilibrium should be around 25% of hands. The equilibrium 3-betting range for the player on the button should be around 7.8% of hands, and the same player’s flatting range should be around 14.7% of hands, leading to a 22.5% non-folding range.
Now let’s imagine that the player on the button is particularly aggressive. We should expect an aggressive player to add in a few more 3-bet bluffs to their range, and perhaps take some hands from their calling range and add them into their 3-betting range as well. So let’s adapt those frequencies so that the button is now flatting around 10.1%, and 3-betting around 25.3%. This is a very wide 3-betting range, and overall it leads to a non-folding range of 35.4%.
This is a pretty reasonable scenario, perhaps slightly more extreme than many real-game situations but not too far removed. It’s also important to note that in this calculation, I’ve left our Nash responses to this villain’s 3-betting ranges unlocked – this means I’m assuming we play well in response to villain’s 3-bets when they do happen, by folding slightly less often and 4-betting slightly more often. I don’t think this is an unreasonable assumption.
Obviously if we configured our calling and 4-betting ranges such that villain was significantly exploiting us with his or her 3-betting frequencies, then I imagine that tightening up our opening range might be a good idea – however, it seems much more logical to figure out an appropriate opening range and then work on how to avoid being exploited thereafter, rather than to figure out a range with which we’re comfortable playing back at our opponents and then turn down potentially profitable opening spots based on our reluctance to deviate from that range.
With all of this in mind, I’ll reveal that the change in our Nash opening range – in other words, the range we should be opening if we have no reliable information about our opponents’ response ranges – is minimal in this spot. It goes from 25.0% at the equilibrium, to 26.4% in this scenario. In other words, even with only four players left to act behind us, having one opponent 3-bet us three times as often as they should be only changes our profitable opening range by a tiny amount, so we shouldn’t let the presence of one aggressive player change our whole strategy.
A final thought about adaptations
The key dynamic at play here is how we respond to our opponents’ increased aggression. If we plan to simply fold to a lot of 3-bets, then of course we should be opening less, because raise-folding more often just creates more easy spots for our opponents to make a profit from us. But what we can see from this analysis is that it’s a far more productive and profitable strategy to focus not on how we should be adapting our opening ranges to cater for the aggression of players behind us (particularly at deep stacks), but rather on how we adapt the ranges with which we play back at their 3-bets once they happen.
In the case of flat-calls, a weak opponent flat-calling too much and creating spots for us to exercise our postflop edge on that player is usually a good thing. So don’t let your fear of getting 3-bet or flat-called affect your preflop opening ranges too much – the deeper the stacks, the more it matters what you do after the 3-bet or the flat-call happens, and not before.