# How To Defend The Big Blind

> Source: [How To Defend The Big Blind on Smarter.Poker](https://smarter.poker/learn/big-blind-defense)

## Executive Summary
Against A 2.5 Big Blind Button Open The Big Blind Needs Only 27.3% Equity To Call, And The Smarter.Poker Reference Defends By Three Betting 7.2% Of Hands And Calling 11.2%, With The Full Chart Below.

- **Category**: Preflop
- **Curriculum**: [Smarter.Poker Strategy Lessons](https://smarter.poker/learn)

## The Big Blind Defending Chart Against The Button

The Chart Is Generated From The Smarter.Poker Preflop Reference, The Same Ranges The Preflop Range Lab Drills. They Are An Authored Teaching Reference For Six Handed Cash At One Hundred Big Blinds, Not A Solver Export, And No Solve Tree Or Checksum Is Attached To Them. Two Sizes Describe A Mixed Range And They Are Not The Same Number. The First Counts Every Hand At The Rate It Is Actually Played, So A Hand Opened Half The Time Counts Half. The Second Counts Any Hand The Range Plays At Least Some Of The Time, In Full.

Each Cell Shows How Often The Hand Three Bets And How Often It Calls When The Button Opens And The Small Blind Folds. What Is Left Over Is A Fold.

### Big Blind Versus A Button Open, 6 Max, 100 Big Blinds: Three Bet And Call Frequency Per Hand

- **Range Frequency**: Continues With 18.4% Of All Starting Hands By Frequency.

## Why The Big Blind Defends So Often

The Big Blind Has Already Put One Big Blind In The Pot, So It Is Closing The Action At A Discount. When The Button Opens To 2.5 Big Blinds And The Small Blind Folds, The Big Blind Calls 1.5 More To Play For A Pot Of 5.5, Which Means A Call Needs Only 27.3% Equity To Break Even Before The Flop. Many Hands That Would Be Clear Folds In Any Other Seat Clear That Bar.

The Cost Is Position. The Big Blind Acts First On Every Street After The Flop, So It Realises Less Of Its Raw Equity Than The Numbers Suggest. The Reference Answers That By Calling With Hands That Make Strong Pairs, Draws And Suited Holdings, And By Three Betting A Mix Of Premium Hands And Suited Hands That Block The Button's Strongest Continues.

## Defence Against Every Seat

The Earlier The Opener, The Stronger Its Range And The Tighter The Big Blind Defends. The Table Shows Both Parts Of The Defence Against Each Seat In The Reference.

Published Solver Solutions For Common Open Sizes Defend The Big Blind Considerably Wider Than This Teaching Reference Does, So Treat These Numbers As A Conservative Floor While You Learn The Structure, Not As A Ceiling. The Shape Is What Transfers: Defend Wider Against Later Seats, Three Bet The Hands That Play Badly As Calls, And Fold The Offsuit Hands That Are Dominated.

### Big Blind Defence By Opener, 6 Max Cash, 100 Big Blinds, Frequency Weighted

| Opener | Three Bets | Calls | Defends In Total |
| --- | --- | --- | --- |
| Under The Gun | 3.1% | 6.4% | 9.5% |
| Cutoff | 4.7% | 9.2% | 13.9% |
| Button | 7.2% | 11.2% | 18.4% |
| Small Blind | 10.3% | 12.2% | 22.5% |

## Key Poker Terms In This Lesson

- [blinds](https://smarter.poker/glossary/blinds) ([Markdown](https://smarter.poker/glossary/blinds.md))
- [pot-odds](https://smarter.poker/glossary/pot-odds) ([Markdown](https://smarter.poker/glossary/pot-odds.md))
- [out-of-position](https://smarter.poker/glossary/out-of-position) ([Markdown](https://smarter.poker/glossary/out-of-position.md))
- [3-bet](https://smarter.poker/glossary/3-bet) ([Markdown](https://smarter.poker/glossary/3-bet.md))
- [under-defense](https://smarter.poker/glossary/under-defense) ([Markdown](https://smarter.poker/glossary/under-defense.md))

## Practice & Interactive Tools On Smarter.Poker

- **Training Drill**: [Play Defense Matrix](https://smarter.poker/hub/training/play/cash-003)
- **Interactive Calculator**: [Open Preflop Range Lab](https://smarter.poker/hub/preflop-charts)
- **AI Coach**: [Jarvis Training Insights](https://smarter.poker/hub/training/jarvis)