Poker course

Defending the Open

I am in the CO. Someone opened. What do I do? Learn every seat's defense, one position at a time.

Reviewed by StackedPoker Theory TeamUpdated 2 min readbeginner

What Defending the Open covers

Learn to defend from every seat — HJ, CO, BTN, SB and BB — building a complete fold/call/3-bet response to an open raise position by position, the same way you built your opening ranges.

I am in the CO. Someone opened. What do I do? Learn every seat's defense, one position at a time.

Learning objectives

  • Build a complete fold/call/3-bet defense range from HJ, CO, BTN, SB and BB against a real open
  • Judge a hand by how it performs against THIS open from THIS seat, not by raw strength alone
  • Weigh price, equity realization, position, players behind and stack depth together before continuing

Lessons in this module

Facing an Open
Your cards are only one part of the decision.
Defending as HJ
One seat past first-in — but still facing a tight, strong range.
Defending as CO
Two openers behind you now — and equity realization starts to matter.
Defending as BTN
When you can call and keep position, more hands can survive.
Defending as SB
A discount helps. Being out of position with the big blind behind hurts.
Defending as BB
You get the best price at the table — and some of the hardest postflop situations.
Stack Depth Adjustments
Stack depth changes what your hand is trying to accomplish.
Build Your Defense Range
Stop solving one hand at a time.
Defense Room
Read the open. Read the table. Build the response.

Key takeaway

Defending the Open is 9 lessons and roughly 172 minutes of interactive work. Learn to defend from every seat — HJ, CO, BTN, SB and BB — building a complete fold/call/3-bet response to an open raise position by position, the same way you built your opening ranges.

Every lesson in Defending the Open

  1. Facing an OpenYour cards are only one part of the decision.6 steps · 12 min
  2. Defending as HJOne seat past first-in — but still facing a tight, strong range.9 steps · 16 min
  3. Defending as COTwo openers behind you now — and equity realization starts to matter.14 steps · 18 min
  4. Defending as BTNWhen you can call and keep position, more hands can survive.12 steps · 18 min
  5. Defending as SBA discount helps. Being out of position with the big blind behind hurts.11 steps · 18 min
  6. Defending as BBYou get the best price at the table — and some of the hardest postflop situations.25 steps · 24 min
  7. Stack Depth AdjustmentsStack depth changes what your hand is trying to accomplish.16 steps · 20 min
  8. Build Your Defense RangeStop solving one hand at a time.13 steps · 20 min
  9. Defense RoomRead the open. Read the table. Build the response.18 steps · 26 min

Frequently asked questions

What is the Defending the Open courseModule?

Learn to defend from every seat — HJ, CO, BTN, SB and BB — building a complete fold/call/3-bet response to an open raise position by position, the same way you built your opening ranges. It contains 9 interactive lessons and takes about 172 minutes to complete.

How long does Defending the Open take?

About 172 minutes in total, split across 9 lessons you can take one at a time.

Is Defending the Open free?

Yes — this module is included on the free StackedPoker plan.

Concepts, lessons and tools that build on this page.

Source: Module structure and lesson list come from the StackedPoker curriculum.