Hey!

Today we'll look at how you can adjust your preflop play against an aggressive opponent. To be specific, we're looking at a spot where we're open raising as the Cutoff and get 3bet by a very aggressive Small Blind.

We'll explore how we should react against their 3bet and also find one other - maybe even more powerful - way to exploit a player who is too aggressive.

How should we adjust if the SB is 3betting much more aggressively than GTO?

Let's find out.

Even though GTO preflop ranges have been available to players for years now, the reality is still that a lot of players don't play perfectly preflop. Which means they'll deviate and be tighter or looser than they should be.

And while most regular players get the raise first in ranges mostly right, actual 3betting ranges still deviate a lot from what would be GTO.

Below you see a GTO opening range for the CO, in this example it's a NL500 rake structure on Pokerstars.

Most people will get that right.

CO GTO opening range

And assuming a 3bet or fold strategy from the SB, which most regulars play, this would be the SB's GTO range facing the open:

SB range vs CO open (GTO)

As we can see, the SB would 3bet 88+ and AQo+ all the time and sometimes 3bet 66 & 77 and AJo & KQo.

On the suited side, broadway hands are always 3bet, as well as A9s and A5s. T9s, K9s, A8s and A4s would be 3bet sometimes.

The overall 3betting frequency would be 10.6%.

Against that 3bet, this would be our continuing range in the CO:

CO range vs SB's 3bet

We're calling a lot of hands: 55+ almost always, AQo+ and every suited broadway hand. We continue all suited connectors we open raised and even hands like J9s & K9s. Regarding suited aces, A9s is always continuing, as well as A5s, A4s and a lot of A3s.

But we also fold a lot of hands. A big chunk of Qxs, Kxs and even Axs hands have to be folded. Even more so on the offsuited side: Everything worse than AJo and KQo is always folding. And since offsuited hands make for 12 combos each, the folding range amounts to 16.8% in total.

4betting hands include most QQ+ and some JJ+ for value and about half of AKo & AKs. And for bluffing hands we use some low to medium frequencies with low and medium suited K- and Ax, like K9s/KTs and A7s/A8s/ATs. But most bluffs come from offsuited hands - KQo, AJo and AQo.

BUT....

...what if SB played more aggressively and simply raised more hands from the SB against our CO open?

Many players simply can't help but raise a lot more hands, whether for a good reason or not.

It's not cazy to imagine a player who doesn't like folding a lot of small pocket pairs, suited connectors and suited aces against a late position open.

How would our approach as the CO look like against such a looser 3betting range?

To get an answer to that question, I ran some preflop sims in Holdem Ressources Calculator (HRC) and input these assumptions.

For this simulation, I assumed the SB to extend their 3betting range to every pocket pair of 66+, every suited ace, 75% of most suited connectors, J9s & K9s and KJo & ATo, 50% of 55 and 100% of AJo.

Adjusted aggressive SB range vs CO's open

In this case, the overall 3betting frequency increases from 10.6% (GTO) to 16.4%.

And in the CO, this would be the range we could continue against that 3bet:

CO range vs aggressive SB 3bet

A LOT MORE hands that we can continue!

Against the adjusted 3betting approach, we can continue with an extremely wide range.

The overall amount of hands we can call goes up from 9.5% (GTO) to 15.5%, so more than a 50% increase.

The bulk of that increase comes from suited hands. We're now calling almost every suited hand we opened! Only the lowest Kxs and Qxs we opened are being folded, everything else can be continued.

But on the offsuited side, the increase isn't as big. KQo and AJo are now almost always calling instead of mixing folding and bluff-4betting. Those action dropped to one hand lower, so now ATo and KJo are playing this part and mix folding and bluff-4betting.

Other than that, not much has changed for the offsuited hands!

All other Tx off hands are still pure folds, just like lower Ax off.

So if we're facing a wider 3betting range from the SB, we absolutely want to focus on the suited part of our range and expand that.

Besides that, we can increase our value 4betting range, as Jacks are now always 4betting, and Tens do so sometimes. Also AKo and AKs are now always 4betting, and we can see that we can even play a 4bet-jamming range which includes AK and JJ.

A Different Adjustment

Another adjustment we could make is to change our opening range.

For all simulations above, I locked the GTO opening range we would be playing in the CO. Reasons for that can be found in the sentence after the next.

But if we know our opponent in the SB is going to 3bet us much wider when we open, we could already let that fact influence our opening range and adjust before they have even placed their 3bet.

This adjustment is a bit more tricky because it can't be isolated, but also brings some of second hand consequenses with it:

• If you change your opening range, it doesn't only affect the SB's play, but also the BTN's and the BB's. If you adjust the range you're continuing against a SB's 3bet, there's noone else in the hand. So noone else could adjust their play and then impact your strategy by adjusting themselves. When you adjust your opening range, the BTN's and the BB's adjustments have a big impact on your EV as well.

• If you change your opening range, your postflop range will look different than before. So if you've been familiar with the GTO preflop ranges and studied those, your postflop strategies would look different if you played different opening ranges.

Which is why the approach of not changing the RFI ranges and simply playing GTO opening ranges is the much more simple and less complex approach. In that case, you only adjust how you react to a 3bet, which only impacts one opponent and a far smaller number of postflop scenarios.

Still, let's have a look at how our opening range in the CO would be affected facing an aggressive 3bet from the SB.

For that, we unlock the RFI range and keep the SB's 3betting range the same aggressive range as before. Also we keep the BTN's and the BB's strategies the same and pretend like they wouldn't adjust to our adjustment.

In that case, our RFI range in the CO would look like this:

Adjusted CO opening range if SB is 3betting aggressive

A lot tighter!

We go from opening 30.4% according to GTO to only 21.2%, so about 1/3 of hands we're just folding now.

However, we then see a funny thing when we look at what we would do against the SB's 3bet:

CO range vs aggro SB 3bet if we opened tighter

We basically don't fold any hands we opened!

Only some QJo & KJo would be folded, but everything else could be continued. Which shows how much impact one player's un-GTO range - in this case the SB's - can have on our opening range. Because remember: both the BTN and the BB still play a GTO range against our open, just like before.

Still, the solver likes to optimize our opening range for the scenario which happens in 16.4% of the time - being 3bet by the SB.

If we compare the simulations with and without the CO's RFI range locked and look at the ranges we play against the SB's 3bet, we see that they're very similar in both cases. So if the solver can choose which hands to open, it would choose to save the amount of big blinds we'd lose by opening those hands we'd then fold against a 3bet.

But how much EV does that gain us? Is this actually worth implementing? Or is it just a theoretical 0.000001BB we would gain in solver land?

Let's have a look.

In HRC, we can see each node's total EV, including all following action.

For the nodelocked opening range, the CO's EV for folding is 0. Because if we fold, we lose 0bb and we win 0bb. Simple. The EV for raising is 0.605bb. So since raising happens 30.4% of the time and folding happens the remaining 69.6% of the time, the average EV for the CO is 0.184bb.

CO's average EV with GTO RFI range (but adjusted reaction to SB's 3bet)

For the unlocked opening range, the EV of folding is of course 0bb again, and the EV of raising is 0.881bb. Since that happens in 21.2% of the time, the combined EV in the CO is 0.187.

Which makes a difference of 0.003bb or 0.3bb/100.

CO's average EV with adjusted RFI range

Is that a lot?

Well, a 0.3bb/100 difference in your winrate is quite a lot! But what's more important for estimating the impact of this number is the amount of times this situation occurs. If you gained an additional 0.3bb/100 in a 4bet pot against 3 opponents on the river, then it wouldn't be that siginificant of an impact. Just because that exact situation maybe occurs once every 1m hands.

But a CO opening spot? The only thing that needs to happen for you to get into that spot is the UTG and HJ player to fold before you. And assuming GTO opening ranges for them, that would happen in 61.5% of the time ((100%-19.4%)*(100%-23.6%)).

Which means it happens really often!

And in that case, a 0.3bb increase is very siginificant.

(Of course, this is based on the premise that the SB is 3betting aggressively).

Again, be aware that adjusting your preflop ranges brings some other concsequences with it regarding other parts of the game tree.

But if you're confident in playing dynamic range pre- and postflop, it is definitely a good idea to adjust your opening range according to the players you have sitting behind you.

Conclusion

If we're in the CO, facing a 3bet against an aggressive 3better in the SB, we want to:

• widen our calling range a lot

  • especially the amount of suited hands

  • but not so much the amount of offsuited hands

• widen our value 4betting range

If we're okay with adjusting our postflop ranges and don't expect BTN and BB to adjust quickly, we can also:

• tighten up our opening range in the CO

• and continue basically every hand we opened when we face the SB's 3bet

As always, you don't have to take the sims above literally and play these exact ranges. After all, the exact approach a solver gives you depends on the inputs, which are always just estimations.

Also, solver outputs rely on the assumption that players play every street perfectly that isn't node locked. Including postflop. Which is not the case - even less so when your opponent has already proven to play imperfectly preflop.

So you're likely able to still play a few hands more profitably that the solver says would be -EV.

However, and that is really important, these simulations show us in which direction you should make adjustments and also whether they are worth making at all. For both, we have found definite answers and you should be able to use them to your advantage!

I hope you got a lot of value out of this.

If you did, you might be interested in Preflop Xploits. Preflop Xploits is a video course that is currently in production.

In it, I am doing exactly what I did in this newsletter and work out the impact of different preflop strategies on our approach. Except I'm doing it for many more spots, positions and player types. The goal is that you'll always know exactly how you can exploit your opponents that don't play perfectly preflop.

Even better, besides experiments like the ones above, I'm working with real population data - so not only assumed preflop ranges, but also actual data from a real player pool (the one I played in).

If that sounds interesting to you, you can sign up to the waitlist to be the first to be notified when the course is released:

All ranges mentioned above have been calculated in HRC and uploaded to PAIRRD by Raise Your Edge.

You can view the ranges in the chart viewer and even play against the solution through the links below for free. All you need is a PAIRRD account, which is free to make in 10 seconds:

CO vs SB GTO:

https://pairrd.com/post/-Nofp2-xFUTOr-9zsvP0/-Nofp65pKmipZGTo-jTK/view?via=2cc

CO (locked RFI) vs aggro SB:

https://pairrd.com/post/-Nog0cR1_jtUJXbijE4W/-Nog0hKiNMfRorVHpPzR/view?via=2cc

CO (unlocked RFI) vs aggro SB

https://pairrd.com/post/-NogkrNT1Gl_krFKLp-i/-Nogkwa_y7Em25E4HeWw/view?via=2cc