progressBB defense vs BTN open at 28 BB
8-max MTT · ante 12.5 % · Button opens, small blind folds · chip EV
How the BB defends at 28 BB
Facing a Button open to 2 BB (small blind folds) with 28 big blinds, the big blind folds only 9.3% of hands, calls 68%, 3-bets to 7 BB with 11% and goes all-in with 12%. 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, AJs, A8s, A3o, A2o, KK, KQs, QQ, JJ.
Always all-in: AJo, ATo, A9o, A8o, A5o, A4o, QJs, 88, 77, 66, 55, 44, 33, 22.
Folded: 94o, 93o, 92o, 83o, 82o, 72o, 62o.
Against other openers at 28 BB the big blind continues with: vs CO 85%, vs HJ 79%, vs LJ 75%, vs UTG+1 73%, vs UTG 72%. 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): 73o 40%, T3o 62%, T2o 38%, Q3o 34%, Q2o 24%. These are the hands worth drilling, because a small change in the opponents or the stack flips them.
What changes around 28 BB
The book continues with 91% of hands here, 90% at 27 BB and 91% at 29 BB. Going from 27 BB to 28 BB, no hand crosses the 50% line; only the frequencies shift. With the extra chips some former all-ins become small raises: A6o.
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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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