OTB #029: The Wildest GTO Strategy You Probably Haven't Heard Of Yet (And How to Defend Against It)

It's the start of the tournament and you're playing 100bb effective.

The BTN opens to 2.26bb, you 3-bet to 10.41bb from the SB with Ah Jc and the BTN calls.

The flop comes Jd Td 2c.

What do you do?

a) Check

b) Bet 25% pot

c) Bet 70% pot

d) Jam (393% pot)

The answer: d) Jam

Today I want to explore this fun spot in more detail and show you which hands you should jam for almost 4x pot, why you should do it and how to defend against it if you're in the Button's shoes.

Let's dive in...

Some hands like to jam

Postflop solvers have taught us many things, like c-betting small in position against the big blind, using a big bet on a blank turn and how the chip leader gets to donk bet more frequently after defending the big blind out of position on a final table.

One more thing to add to that list is that there is some jamming on some boards in 3-bet pots out of position.

Even for 4x pot at 100bb effective. And as you get shallower, there is even more open jamming.

While there isn't much jamming (just 0.39%) at 100bb on the flop, there are some boards that stand out:

JTx flush draw boards have the highest frequency of c-bet jams.

At 60bb, there's more jamming (1.55%) and it's on slightly different boards. T9x boards are the most common this time:

By the time we get to 30bb, there's 3.23% jamming and the T9x boards really stand out once again:

If nobody is doing this in your games, then they're going to struggle to know how to defend against it, which is great for you.

And if you've seen this strategy in your games, but didn't know how to defend against it before now, then the next section should really help.

Why do they like a jam?

On a JT2fd board you have an equity advantage (58.44% vs 41.56%) and a nut advantage (5.2% vs 3.6%), if we assume that means two pair or better.

You also have a slightly higher proportion of top pair (15.5% vs 13.9%) and 2nd pair hands (16.3% vs 13.2%) and of course you have more overpairs than your opponent too (9.7% vs 1.0%).

The solver believes that the highest EV way to play your exact hand is to jam 100% of the time, so why is that?

It's all in the logic. GTO

When you jam a hand like AJo it's for value because you can get called by worse hands like KJ, QJ, nut flush draws and the weakest flush draws with backdoor straight draws, while denying equity to straight draws and some of the middling flush draws.

Getting a hand like Kd7d or KQo with ~46% equity to fold is a huge win. If you bet 70% pot the Button can just call with those hands.

When you jam KQo it's mainly as a bluff because you can get better hands to fold like most Tx and 33-99, you block the hands that can call, like KJ and QJ, and you have decent equity against the calling range.

And when you jam a hand like AK you can get the same better hands to fold, while also getting worse hands to call like nut flush draws and some weak flush draws.

How do you defend against the jam?

Even if you know that the SB never has a really strong hand here like a set or two pair you have to fold a lot. They can still have AJ or an overpair like QQ and you need to have enough equity, about 44.35%, to call.

Jc9c has 45.11% equity against the jamming range and is a call, while Jc8c has just 43.99% and is a fold.

Here's a breakdown of hands you should call:

• Sets (JJ, TT and 22)

• Two pair (JTs and JTo)

• Overpair (AA)

• Top pair (AJ, KJ, QJ and Jc9c)

• 2nd pair (KcTc, QcTc, Tc9c, KdTx and QdTx)

• Combo draws (KdQd, Kd9d, Qd9d, Qd8d, 9d8d, 9d7d, 8d7d)

• Nut flush draws

• Weak flush draws with a backdoor straight draw (6d5d, 5d4d, 5d3d, 4d3d)

Everything else just has to fold.

Today's action tip: Drill and explore SB vs BTN 3-bet pot postflop strategies.

That's it for this week.

See you next Saturday.