Chapitre 11: Call BB HU (GTO)

In this chapter and the next one, you will learn how to correctly defend the Big Blind (BB) against an opponent’s all-in in Heads-Up play.

This is the BB vs SB all-in (Heads-Up) situation in the charts.

And it’s an important change compared to the previous chapters: here, you are reacting to your opponent’s action. These chapters are therefore focused on defense, not aggression.

🧠 These two chapters are among the most technical in the course.

Take your time, it's completely normal that the learning process is gradual.

🎯 Chapter objective

We will analyze the GTO call ranges from the BB in Heads-Up, meaning the theoretically optimal ranges for:

  • Playing against competent opponents (especially if you play €5 / €10 and above)
  • Playing against very short recreational profiles (5–6 BB), where decisions become extremely sensitive

Be careful, these ranges are more complex than they appear!

In this chapter, we will study the GTO strategy for the BB vs SB all-in situation. In the next chapter, we will study the Exploitative strategy.

⚖️ Why are these ranges difficult?

1️⃣ Opponents' push frequencies vary a lot

At the tables, your opponents will often have very different push frequencies from one another. Even between two recreational players, behaviors can vary drastically.

Of course, since this is a GTO chapter, opponent adaptation shouldn’t be the main focus.

But I’m mentioning it anyway to emphasize that these charts should not be applied rigidly, except against regulars who play perfectly GTO. Keep this idea in mind.

Adaptations against recreational players will be explored in the next chapter.

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➡️ Direct consequence: you will often need to adjust your ranges depending on your opponent, sometimes even against certain good players. In short, you will rarely play purely GTO.

  • Against a regular player, you will call a lot, because their pushing range is wide. This corresponds to the GTO call ranges studied in this chapter.
  • Against a recreational player, you will often call much less, because they shove tight.

Again, we’ll dive deeper into these adjustments in the next chapter.

Keep in mind that your opponents will rarely play perfect GTO, meaning you will frequently deviate from pure GTO strategy at the tables.

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2️⃣ The logic behind calls is not always linear

One might think that the shorter the stack gets, the more marginal hands you can call, but that’s not necessarily true.

The GTO calling ranges do not follow a simple progression.

Classic example

Suited connectors (like 87s) may:

Be a call when deep

Become a fold around 10–14 BB

Become a call again when very short

Why?

Because the SB’s pushing range changes depending on the effective stack.

  • With a deeper stack, since the SB pushes mostly hands like 22 and A5o, 87s becomes a profitable call.
  • But shorter (below 14 BB), the SB starts pushing hands like A7 or A8. 87s becomes dominated and loses EV → you must fold.

Key takeaway: a hand that is a call when deep is not always a call when shorter.

🧠 Tips for learning efficiently

There is a lot to learn in this chapter, so here are a few tips to help you memorize the call ranges more easily:

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1. Useful benchmarks

Here are a few simple rules that will serve as anchors:

  • From 2.7 BB: the Big Blind calls 100% of hands
  • From 3.4 BB: the Big Blind calls 100% of SUITED hands
Just like in the SB Push charts in Heads-Up, we highlighted these thresholds in red and green to help with memorization.

2. Know the “block of hands that always call”

Certain hands are automatic calls regardless of your stack size.
Knowing them helps you build confidence and speed up your decision-making.

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3. The exceptions (12–19 BB)

These are the famous hands mentioned earlier, the ones that call when deep, then fold, then call again when very short.

In the final summary chart, these hands are shown with an interval, representing the stack sizes at which they should not be called.

👉 These details concern only mid- and high-stakes regulars.

They will appear in the “Hardcore mode” questions.

You don’t need to learn them if you mainly play low-stakes against recreational players.

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4. The real core difficulty: the 3–8 BB zone

This is a zone you will encounter frequently, and where you must maximize EV.

Once you master the 3–8 BB zone inside out, you’ve completed a very large part of the journey.

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And if you want to dive deeper, feel free to read the SB vs BB all-in Strategic Guide (Heads-Up), which is an excellent complement to this chapter!

💨 Finally, if you play low stakes… breathe.

You don’t need to learn every detail to be a winning player.

Focus on:

  1. Understanding good approximations (which hands to call depending on stacks).
  2. Mastering the calling thresholds between 2 and 4 BB, since these spots occur often and are costly.
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