Big Blind Defense: How to Build a Calling and Shoving Range

The big blind is the one seat that never has to open a pot to see action - it only ever reacts to a price someone else has already set. That changes the question. An opening range asks "which hands are worth starting a pot with?" A big blind range asks "which hands are worth continuing with, now that I know the price and who set it?"

What is a continuing range?

Every chart on this page is the big blind's continuing range - call or shove, whichever the solver prefers, combined into one non-fold frequency per hand. At these stack depths there's rarely a real difference between the two: calling and shoving both put effectively all your chips at risk once you're short, so the meaningful line isn't call-vs-shove, it's continue-vs-fold.

Why does the opener matter so much?

The same big blind, the same 10bb effective stack, against two different opens. Under the gun has the whole table left to act behind it, so an under-the-gun open is a strong range on average - the big blind can only afford to continue with 18% of hands. The button opens last, with nothing but the blinds behind it, so a button open is full of hands that only raised because no one was left to punish it - the big blind can profitably continue with 31% of hands against that, roughly 72% wider than against the tighter open.

How does stack depth change Big Blind defense?

Both ranges get meaningfully wider the shorter the stacks get, for the same reason covered in the stack-depth guide: less behind means a call or shove risks less in absolute terms, and the opener's range doesn't get proportionally stronger just because the stacks got shorter. At 5bb effective the Big Blind continues with about 53% of hands against UTG and about 66% against the Button. Both are far wider than at 10bb, and the two get closer together: when the shove is that small, the price matters more than who made it.

Going the other way tightens it just as sharply. The big blind's 20bb chart against a button open continues with a much narrower slice than the 10bb one above, for the mirror-image reason: the pot you are playing for has not grown, but the stack you have to risk to contest it has doubled. Same opener, same position, twice the price.

Find the matching call-or-fold reference by shover position, stack depth and table size. Browse calling ranges