What does 20bb mean in poker? Stacks explained

How to count your stack in big blinds

Divide your chips by the big blind. The answer is your stack in big blinds, written bb.

• With blinds of 100 and 200, a stack of 4,000 chips is 20bb.
• With blinds of 500 and 1,000, it takes 20,000 chips to have 20bb.
• The ante does not change the count: it is still chips divided by the big blind.

In a hand, what counts is the effective stack: the smaller of your stack and the stack of the player you are up against. If you have 30bb and the only player left to act has 20bb, you can win or lose no more than 20bb against them, so you play a 20bb hand. The charts here give every seat 20 big blinds.

Why players count in big blinds

Blinds rise all through a tournament, so a count of chips says little on its own. 20,000 chips is a big stack early and a short one late. In big blinds, the same stack means the same decision at any level.

Measured against the pot, 20bb is not much. With both blinds and a big blind ante, 2.5bb are in the pot before anyone acts, so a 20bb stack is 8 times the pot you are trying to win. An open to 2bb already puts 10% of it in.

20bb sits between push/fold and deeper play

At 15bb and below, the charts are push/fold: every hand goes all-in or folds. From 40bb, a seat opens to 2bb and the next seat can 3-bet to a size. 20bb is in between, and the button shows it:

The button folded to, in an 8-max tournament with a big blind ante. Shares are of all 1,326 starting combinations.

At 20bb there is still a sized open, but every re-raise is all-in: a seat that wants to raise over an open puts in the whole stack.

What each seat does at 20bb when folded to

Raises are to 2bb, and to 3bb from the small blind. The small blind also limps 51% of hands, which is counted in what it plays.

From under the gun to the lojack, every open is a raise to 2bb. The first seat that ever opens all-in is the hijack, with JTs, AJo, and the shoves grow seat by seat to the button's 13%.

The small blind plays 84% of hands but rarely raises to a size: it limps 51% of hands and goes all-in with 33%, because only the big blind is left to act behind it.

Which hands shove at 20bb

On the button the solver goes all-in with:

55-22, A5s-A2s, Q9s, J9s, T8s+, 98s, 87s, 76s, ATo-A4o, KJo+, QJo

These are hands worth playing but awkward to raise and then face a shove with. A 2bb open that meets an all-in has to call for the whole stack or give up its 2bb. Going all-in first wins the blinds and antes whenever everyone folds, and never has to make that choice. The strongest hands, aces among them, still raise to 2bb: they are glad to be shoved on.

Facing an open at 20bb

Against a button open, the big blind's answer changes between 20bb and 40bb:

• At 20bb it re-raises all-in with 21% of hands, calls with 64% and folds 14%.
• At 40bb it 3-bets 12%, calls 78% and folds 10%.

When the small blind shoves over the button's 2bb open, the button calls with 40% of the hands it opened with, and folds the rest.

Big blind defense chart at 20bb3-bet ranges at 20bb

Using the 20bb charts

• Count your effective stack in big blinds before each hand, and use the chart for the closest depth.
• With a stack between two solved depths, neither chart is exact: pick the closer of the 15bb push/fold chart, the 20bb charts and the 40bb charts.
• These charts are for eight players with a big blind ante, and they maximise chips. Near the bubble or at a final table, prize jumps usually call for tighter play than any chip chart shows.

All 20bb preflop chartsHow to read a poker range chartHow to memorize poker ranges10bb vs 15bb: when to shove in pokerHow stack depth changes preflop play in poker