progressBB defense vs CO open at 50 BB
8-max MTT · ante 12.5 % · Cutoff opens, small blind folds · chip EV
How the BB defends at 50 BB
Facing a Cutoff open to 2.1 BB (small blind folds) with 50 big blinds, the big blind folds only 22% of hands, calls 65%, 3-bets to 9.5 BB with 13% and goes all-in with 0.1%. The big blind already has one blind in the pot and closes the action, so it gets a good price.
Always 3-bet: AA, AKs, AKo, AQs, AQo, AJs, AJo, ATs, KK, QQ, JJ, TT, 99, 88 and 1 more.
Folded: Q6o, Q5o, Q4o, Q3o, Q2o, J2o, T5o, T4o, T3o, T2o, 94o, 93o and 7 more.
Against other openers at 50 BB the big blind continues with: vs BTN 88%, vs HJ 78%, vs LJ 74%, vs UTG+1 73%, vs UTG 70%. 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): 63o 56%, 52o 42%, K3o 60%, J4o 40%, K2o 36%, J5o 66%. These are the hands worth drilling, because a small change in the opponents or the stack flips them.
What changes around 50 BB
The book continues with 78% of hands here, 79% at 45 BB and 78% at 55 BB. Going from 45 BB to 50 BB, no hand crosses the 50% line; only the frequencies shift.
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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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