progressBB defense vs CO open at 21 BB
8-max MTT · ante 12.5 % · Cutoff opens, small blind folds · chip EV
How the BB defends at 21 BB
Facing a Cutoff open to 2 BB (small blind folds) with 21 big blinds, the big blind folds only 16% of hands, calls 67%, 3-bets to 6 BB with 1.3% and goes all-in with 16%. The big blind already has one blind in the pot and closes the action, so it gets a good price.
Always all-in: AKs, AKo, AQo, AJs, AJo, ATs, ATo, A9o, A5o, A4o, KK, KQs, K6o, QQ, JJ, TT and 8 more.
Folded: Q5o, Q4o, Q3o, Q2o, T5o, T4o, T3o, T2o, 94o, 93o, 92o, 83o and 4 more.
Against other openers at 21 BB the big blind continues with: vs BTN 86%, vs HJ 80%, vs LJ 78%, vs UTG+1 75%, vs UTG 73%. The later the opener, the wider its range, and the more the big blind defends.
Closest decisions (the book continues with them only part of the time): Q6o 46%, J3o 68%, 84o 68%, J2o 22%. These are the hands worth drilling, because a small change in the opponents or the stack flips them.
What changes around 21 BB
The book continues with 84% of hands here, 84% at 20 BB and 84% at 22 BB. These leave it: Q6o. With the extra chips some former all-ins become small raises: AA, AQs.
Free 7-day ICM course by e-mail
One short lesson a day, each with a worked example in exact numbers: chips vs. money, the bubble factor, who feels the pressure, payout structures, satellites. No account needed.
Numbers come from the progressGTO solution book (v14, chip EV, 8-max, ante 12.5 %): our own equilibrium computation with a modelled postflop. It is an approximation, not an exact solution, and it keeps improving. Hover or tap a hand to see its exact frequencies.
progressGTOAll rangesGuidesDaily spotICM calculatorOpen the appPrivacyTerms