At a glance
- On the HUD
- BBDef
- Formula
(steals faced in the BB − folds) / steals faced in the BB- Typical range
38–65%
- Where it shows
- In the player database, where you can see every stat for a player (not on the table badges).
- Trust it after
- 12 chances. Below that the number is faded; reads need 12 chances and a number at least one standard error outside the typical range.
What it measures
Big blind defense is the share of steals the big blind doesn’t give up. Any answer other than a fold counts: a flat call or a 3-bet. It’s the way most strategy talk frames the big blind (“defend wider against the button”), so the HUD keeps it as its own number even though it’s the same information as BB fold to steal, turned over.
It has two parts that matter as much as the total: BB call vs steal (the flats) and BB 3-bet vs steal (the re-raises). Two players defending 55% can be completely different: one calls 50% and 3-bets 5%, the other calls 35% and 3-bets 20%.
It covers the big blind only, against steals only. Opens from early seats, and pots where someone already called the open, are outside it; fold vs open covers every open from every seat.
How it’s calculated
BBDef is worked out from BB fold to steal, not counted on its own:
- BBDef = (steals faced in the big blind − folds) / steals faced in the big blind = 100% − FtS-BB
The sample behind it is the number of steals the player faced in the big blind. A steal faced means: they were in the big blind, the first raise came from the cutoff, button or small blind with no limpers before it, and their first action after it faced that one raise with nobody calling in between. If the small blind calls or 3-bets first, the big blind has no chance in that hand.
Because it’s 100% minus a fold rate, every non-fold counts, including an all-in call from a short stack. That’s why calls plus 3-bets can come out a touch different from BBDef: 3-bet vs steal only counts hands where the player had chips to raise.
BBDef itself is one overall number. FtS-BB is also kept by the stealer’s seat, so defense against one seat is 100% minus that version.
Example: Leo faced 40 steals in the big blind and folded 18 → FtS-BB = 18 / 40 = 45%, so BBDef = 22 / 40 = 55%. His 22 defenses were 16 calls and 6 3-bets.
Why it matters
Defense is what stops stealing from being free. A 2.5 bb steal risks 2.5 to win the 1.5 in the blinds, so any two cards profit on the spot unless the blinds together continue more than 1.5 / (1.5 + 2.5) = 37.5% of the time. When the small blind raises to 3 bb, it puts in 2.5 more to win the same 1.5, so the big blind alone has to defend more than 37.5%. The bottom of the typical range, 38%, sits right on that line.
Clearing that line isn’t the goal, though; the price is. Against a 2.5 bb button open the big blind calls 1.5 more into a 4 bb pot and needs only 1.5 / 5.5 = 27.3% equity, which is why in most games a solid big blind defends more than half its hands against the button and less against the tighter cutoff.
For you, BBDef answers two questions: how wide can you steal into this player, and how wide is their range when they call. A high number means more flops against a weak, wide range; a low number means more pots won preflop.
Too low, about right, too high
Too low: under 38%
What it says
They give up more than 62% of steals, so even a small blind steal with any two cards is close to profitable against them before the flop. This is a tight player who doesn’t want to play out of position: a Nit or Rock, or a regular who folds the bottom of the range out of habit. When they do defend, they hold a strong, narrow range. FtS-BB carries the read for this spot: “Overfolds the BB: steal more.”
How to exploit it
- From the small blind, raise almost every hand. A raise to 2.5 bb puts in 2 more to win 1.5 and needs 2 / 3.5 = 57.1% folds, less than this player gives you.
- Widen your button and cutoff steals, then check the small blind too: from the button both blinds must fold.
- Keep your steals small. A big blind who overfolds rarely starts defending just because the price got better, so a smaller open wins the same pots for less risk.
- Give their defenses credit. A big blind defending 30% has few weak hands left, so c-bet less as a bluff and fold more to their check-raises.
About right: 38–65%
What it says
The player defends a reasonable share of hands for the price. Look at the shape inside the total. Mostly calls with few 3-bets means a passive, uncapped range: strong hands hide among the calls. A real share of 3-bets means a capped calling range and more pressure on your light steals. Compare the seat versions too; a good player defends more against the button than the cutoff.
How to exploit it
You won’t win much just by raising, so play the pot well afterward. Against a calls-heavy defense, bet small and often on high-card boards and keep barreling turn overcards; their flats rarely hold top pair with a good kicker. Against a 3-bet-heavy defense, steal hands that can call a 3-bet in position and drop those that can’t. Then look for the postflop leak: fold to c-bet and check-raise frequency after they defend tell you where the money is after the flop.
Too high: over 65%
What it says
They defend nearly two steals in three or more, which means many hands that can’t win much after the flop: offsuit junk, weak kings and queens, any suited cards. Fish and Stations sit here, and in home games so do players who see the big blind as already half in. FtS-BB is under 35% in this case, and that stat makes the read “Defends wide: steal tighter, value-bet more.”
How to exploit it
- Steal tighter. Hands that only win when everyone folds lose money; hands that make strong top pairs gain.
- Open bigger with your value hands. A wide defender calling 3 bb instead of 2.5 bb pays you more with the same range.
- Value-bet thinner on every street. Top pair with a medium kicker is usually ahead of a range this wide.
- Bluff where their range misses: c-bet ace-high and king-high flops, and give up more on low, connected boards that hit their suited and connected hands.
When it’s your own number
BBDef has no read hint of its own, but your FtS-BB does, and it’s the same number turned over. Defend too little and opponents get the read to “steal more when you’re in the big blind.” Defend too much and they get “steal less against your big blind and value-bet you more.”
Check yours against the price you’re getting. Against a 2 bb steal you need 22.2% equity (1 to call into a 4.5 bb final pot); against a 3 bb steal, 30.8% (2 into 6.5). Defend most against small blind steals, where you have position, then the button, then the cutoff. If your defense is under 38%, add suited and connected hands first.
Using it on the HUD
BBDef is in the player database only, not on the table badges. There it uses the usual colors: gold over 65%, blue under 38%, faded with fewer than 12 steals faced. It makes no reads.
At the table, the same information sits on the big blind’s badge as FtS-BB, and the colors mirror: a gold BBDef is a blue FtS-BB, and the other way round. When you can steal, the panel shows the big blind’s fold rate against your seat, which is 100% minus their defense against you.
Give it time. Each chance is one steal faced in the big blind, so samples grow slowly: a 50% number over 30 chances is ±9 points, over 100 it’s ±5. Read it with its parts, BB call vs steal and 3-bet vs steal, and with the stealer’s open size.
Questions
What is a good big blind defense percentage against steals?
The HUD treats 38–65% as typical. In most games a solid big blind defends toward the upper part of that range against button and small blind steals and less against the cutoff, because the button and small blind open wider. Bigger opens give a worse price, so defense should drop as steal sizes grow.
How is BB defend vs steal calculated?
It’s 100% minus BB fold to steal. The HUD counts the steals a player faced in the big blind and the times they folded; every other answer, a call or a 3-bet, is a defense. A player who faced 40 steals and folded 18 has a BB fold to steal of 45% and defends 55%.
What is the minimum defense frequency for the big blind?
Against a small blind raise to 3 bb, the small blind puts in 2.5 more to win 1.5, so the big blind must continue more than 37.5% of the time or any two cards profit immediately. Against a 2.5 bb button steal, which also risks 2.5 to win 1.5, both blinds share that 37.5%. In practice the big blind should defend well above that, because the price to call is good.
Why should the big blind defend more against the button than the cutoff?
Because the button opens a wider, weaker range than the cutoff, so more of the big blind’s hands play well against it. The price is the same for the same open size, but the opponent’s range is worse. A big blind who defends the same amount against both is probably folding too much against the button.