progressBB defense vs CO open at 18 BB
8-max MTT · ante 12.5 % · Cutoff opens, small blind folds · chip EV
How the BB defends at 18 BB
Facing a Cutoff open to 2 BB (small blind folds) with 18 big blinds, the big blind folds only 17% of hands, calls 65%, 3-bets to 5.5 BB with 0.4% and goes all-in with 18%. The big blind already has one blind in the pot and closes the action, so it gets a good price.
Always all-in: AA, AKo, AQo, AJs, AJo, ATs, ATo, A9o, A6o, A5o, A4o, KK, K6o, QQ, QJs, JJ and 9 more.
Folded: Q6o, Q5o, Q4o, Q3o, Q2o, J2o, T5o, T4o, T3o, T2o, 94o, 93o and 6 more.
Against other openers at 18 BB the big blind continues with: vs BTN 84%, vs HJ 80%, vs LJ 77%, vs UTG+1 75%, vs UTG 74%. 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): J3o 52%, 84o 48%. These are the hands worth drilling, because a small change in the opponents or the stack flips them.
What changes around 18 BB
The book continues with 83% of hands here, 82% at 17 BB and 84% at 19 BB. Compared with 17 BB, these hands come into the range: J3o.
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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.
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