progressBB defense vs UTG open at 18 BB
8-max MTT · ante 12.5 % · Under the Gun opens, small blind folds · chip EV
How the BB defends at 18 BB
Facing a Under the Gun open to 2 BB (small blind folds) with 18 big blinds, the big blind folds only 26% of hands, calls 66% and goes all-in with 8.0%. The big blind already has one blind in the pot and closes the action, so it gets a good price.
Always all-in: AA, AKs, AKo, AQs, AQo, KK, QQ, JJ, TT, 99, 88.
Folded: K6o, K5o, K4o, K3o, K2o, Q7o, Q6o, Q5o, Q4o, Q3o, Q2o, J5o and 15 more.
Against other openers at 18 BB the big blind continues with: vs BTN 84%, vs CO 83%, vs HJ 80%, vs LJ 77%, vs UTG+1 75%. 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): 95o 60%, 84o 32%. 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 74% of hands here, 74% at 17 BB and 73% at 19 BB. Going from 17 BB to 18 BB, no hand crosses the 50% line; only the frequencies shift. Some hands switch to an all-in: KTs, 44.
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