Big blind defence is the spot you play more than any other, and the one where most players lose the most without noticing. Every orbit someone opens, the action folds to you, and you have to decide in a couple of seconds whether to fold, call or 3-bet. Against a min-raise the answer is "defend" far more often than feels natural. This guide covers how wide to defend, which hands to call and which to 3-bet, and how the answer changes with position, raise size, antes and rake.
Why the big blind defends so wide
You've already put 1bb in the pot, so you're never paying the full price of the raise. Against a min-raise the price is very good:
| Spot | Open | You call | Final pot | Equity needed |
|---|---|---|---|---|
| Cash, no ante | 2bb | 1bb | 4.5bb | ~22% |
| Cash, no ante | 2.5bb | 1.5bb | 5.5bb | ~27% |
| Cash, no ante | 3bb | 2bb | 6.5bb | ~31% |
| MTT / Spin with BB ante | 2bb | 1bb | 5.5bb | ~18% |
Even 7-2 offsuit has around 30% equity against a typical button opening range. That doesn't mean you call it, because raw equity isn't what you actually win.
Equity realisation: the reason you still fold some hands
Out of position, you won't get to see a showdown with all of your equity. You'll check-fold some flops where you had outs, and get bluffed off hands that were winning. Solvers account for this, and the hands that realise their equity worst are weak offsuit hands with no connectivity: 8-3o, 9-2o, T-4o. Those make bottom pair with a bad kicker and rarely make strong draws.
Suited hands are the opposite. Flush draws, backdoor draws and the ability to make strong hands on many boards let them realise much more of their equity, so almost every suited hand defends against a late-position min-raise.
How wide to defend, by opener
The later the open, the wider the opener's range, and the wider you defend. A rough GTO picture for the big blind against a single opener:
| Opener | 6-max cash, 2.5bb, 100bb | MTT, 2bb with ante, ~40bb |
|---|---|---|
| UTG / early | ~25–30% | ~40–45% |
| CO | ~35–40% | ~50–55% |
| BTN | ~45–55% | ~60–70% |
| SB | ~55–65% | ~65–75% |
Treat these as orientation, not targets. Exact numbers move with rake, raise size and the solver's bet-size settings. What doesn't move is the shape: against a button min-raise you should be defending roughly every other hand or more, and in formats with antes, most of the deck.
What the folds look like
Against a button min-raise with antes, the folding range is mostly weak offsuit hands: offsuit hands with a low card that don't connect, like 8-2o, 7-3o, T-3o, 9-4o and Q-2o in some setups. If your fold pile regularly contains suited hands, offsuit broadways or connected offsuit hands like 7-6o and 8-6o, you're over-folding.
Calling vs 3-betting
Defending isn't just calling. Your 3-bet range does two jobs: it gets value from the hands the opener continues with, and it stops your calling range being an easy target.
Against early positions: linear and value-heavy
Early-position ranges are strong, so 3-bet bluffs get called or 4-bet too often. The big blind 3-bets mostly premium hands (QQ+, AK, some AQs, KQs) and flats almost everything else it defends. Calling here is the main way to defend.
Against late positions: wider, with blockers
Against the button and small blind, the big blind 3-bets much more, and the range gets a polarised element. Strong hands go in for value, along with hands that block the opener's continuing range and play poorly as calls: suited aces like A5s–A2s, suited kings, and some offsuit broadways that would be dominated if they just called.
At short stacks: the 3-bet becomes a shove
Below about 20–25bb, a non-all-in 3-bet leaves too little behind to fold, so most 3-bets become 3-bet shoves. Calling ranges stay wide, and the hands that used to 3-bet as a bluff move into either the shove range or the fold range. Our push/fold guide covers the jam ranges in detail.
What changes the answer
Raise size
Every extra fraction of a big blind the opener adds makes your price worse. Against a 3bb open from the button you defend noticeably tighter than against 2bb, and the weakest offsuit hands drop out first. This is also why min-raising is so popular in formats with antes: it gives the big blind a great price, but risks less when the open gets 3-bet.
Antes
Antes put more dead money in the pot, which improves your price again. That's why the MTT column in the table above is so much wider than cash. See our MTT strategy guide for how antes and ICM reshape the rest of the preflop strategy.
Rake
In cash games, rake is taken from pots that see a flop. Calling and playing a small pot is exactly what rake punishes, so at low stakes with high rake the big blind calls tighter and shifts a little more into 3-betting. At higher stakes with lower rake, calling ranges widen again. Our 6-max cash ranges go through the stake-by-stake differences.
ICM
Near the bubble and at final tables, losing chips costs more than winning them gains, and the big blind has to tighten, especially against covering stacks. A chip-EV chart will tell you to defend hands that ICM folds.
After the flop
A wide defence only works if you continue playing well after the flop. Two habits matter most:
- Don't over-fold to c-bets. You defended a wide range on purpose; folding everything that missed hands the opener a free profit. Continue with pairs, draws, backdoor draws and overcards that have good outs.
- Use the check-raise on boards that favour you. Low, connected boards hit the big blind's range much harder than the opener's. That's where your strongest hands and best draws should go for a raise. Our BTN vs BB guide breaks down which boards are which.
Common big blind mistakes
- Folding the big blind like any other position. The 1bb you posted makes this the cheapest place at the table to see a flop.
- One range for every opener. Defending the same hands against UTG and the button means you're too loose against one and too tight against the other.
- Ignoring raise size. 2bb and 3bb opens need different ranges.
- Flatting everything. A big blind that never 3-bets is easy to attack.
- Copying cash charts into tournaments. Antes change the price enough to change the range. Use charts built for your format and stack depth.
How to drill it
The big blind comes up once an orbit, so small improvements here add up fast. A simple order of study:
- Learn the defend/fold boundary against the button at the stack depth you play.
- Add the 3-bet range for that spot.
- Repeat for the CO, then early positions, so you feel the range tighten.
- Repeat for the raise sizes you see most in your games.
Drill each spot with a GTO poker trainer until the decision is instant, then check your own hands to see whether your real big blind defence matches the chart.
Frequently asked questions
How much equity does the big blind need to call a min-raise?
About 22% in a cash game without antes, and about 18% with a big blind ante, because the dead money improves the price.
How often should the big blind defend against a button min-raise?
Roughly half the hands or more at 100bb in cash, and most of the deck in formats with antes. Exact frequencies depend on rake, stack depth and raise size.
Which hands should the big blind fold against a min-raise?
Mostly weak, unconnected offsuit hands such as 8-2o, 7-3o and T-3o. They realise their equity poorly out of position. Almost all suited hands defend against a late-position min-raise.
Should the big blind 3-bet or call?
Both. Against early positions the big blind mostly calls and 3-bets a value-heavy range; against late positions it 3-bets more, adding blockers such as suited aces. Below about 20-25bb most 3-bets become all-ins.