Blog · Strategy
Defending your big blind: what range to play against a raise
Your big blind defending rangedepends on two things: the opener's sizing (the smaller it is, the wider you defend) and their position (the further the open comes from the button, the stronger it is and the tighter you defend).
Why the big blind defends wider than other positions
You've already put your blind in before the action even starts: your pot odds to call an open are therefore better than any other player's at the table. That's the structural reason your BB defending range should be wider than your calling range from other positions.
Your range based on the opener's sizing
Open to 2 - 2.2x (small sizing)
You're already well invested in the pot and getting a very favorable price to call. Defend wide: most pairs, all suited Aces, plenty of suited connectors, and medium offsuit hands.
Open to 2.5 - 3x (standard sizing)
The most common sizing at Winamax micro-limits. Your defending range stays wide but a notch tighter than against a small sizing — you cut the weakest offsuit hands.
Open to 4x and above (large sizing)
Your pot odds get worse: you need to defend tighter and favor hands that win big (pairs, strong suited hands) over speculative hands that need a good price to be profitable.
Your range based on the raiser's position
Open coming from the button or the SB
The opening range there is the widest (see our article on ranges by position) — so your defending range should be too. This is where you defend the most combos, both calling and 3-betting.
Open coming from the CO
An intermediate defending range: you cut the most marginal hands you'd defend against the button, but you stay wider than against an early open.
Open coming from UTG or MP
The opening range there is the strongest at the table: your defense needs to tighten noticeably, focusing on your best pairs, your best suited Aces, and a handful of strong suited connectors.
Calculating your exact defense frequency
The reference points above are enough in play, but for a precise situation (exact sizing, exact stack), the FlopIQ BB Defense tool calculates your minimum defending frequency directly — the article explains the why, the tool gives you the exact number for your table.
Frequently asked questions
What is MDF (minimum defense frequency)?
It's the minimum frequency at which you need to defend (call or 3-bet) to avoid being exploitable by an opponent who bluffs. In practice, the bigger your opponent's sizing, the lower this minimum frequency drops — but the idea to remember is simple: defend wider against a small sizing, tighter against a large one.
Should you defend the same range calling as 3-betting?
No. Your calling range gathers hands that play well multiway or out of position (small pairs, suited connectors), while your 3-bet range gathers your best value hands and a few polarized bluffs — see our dedicated article on building a 3-bet range.
Why does the big blind defend wider than other positions?
Because you've already put a forced bet into the pot before the action even starts: your pot odds to call an open are therefore better than those of a player who hasn't put in any chips yet.
Is a precise calculation necessary on every hand?
No, the reference points by sizing and by position are enough in play. For a precise situation (exact sizing, exact stack), the FlopIQ BB Defense tool calculates the right defending frequency directly.
Find out if you're defending too tight from the big blind
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What FlopIQ does on this topic
The FlopIQ tools and analyses that directly address what you just read.
Big blind defense
The range to defend based on the opener's position and their open size.
See defense ranges →BB Defense Trainer
Defend or fold your big blind, with the MDF reasoning walked through situation by situation.
Train my BB defense →Range Manager
An editable 13×13 matrix, GTO-inspired standard ranges by position — and your actually-played ranges, extracted from your history and overlaid on the reference.
Open the Range Manager →