PokerSolver
PokerSolver/4-max · 100bb · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb/BB vs CO all-in

BB vs CO all-in

4-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb (blinds 0.5/1bb, ante 0.16bb) · 100bb · CO limps, BB isolates to 3bb, CO 3-bets to 9bb, BB 4-bets to 20.7bb, CO goes all-in · Big blind to act

4-max · 100bb · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bbChange game
Stacks (bb), if they differ
Pot 121.68bbYour cards?
20.7bb
99.84bb
0.5bb

Tap your two cards.

Big blind's range

298 of 1,326 combos get here
Fold 76.9%Call 23.1%
Tap a hand, or type one above, to see its exact mix.

What is the GTO play for the big blind (BB) when CO limps, BB isolates to 3bb, CO 3-bets to 9bb, BB 4-bets to 20.7bb, CO goes all-in in 4-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb at 100bb?

CO limps, BB isolates to 3bb, CO 3-bets to 9bb, BB 4-bets to 20.7bb, CO goes all-in in 4-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb, 100bb: the big blind (BB) folds 76.9% and calls 23.1%. Always call: QQ+, TT. Mixed: 55-99, AJs+, A8s-A9s, A5s, KJs+, Q9s, JTs, J8s, 86s+, 54s, AKo.

Always fold
JJ, ATs, A6s-A7s, A3s-A4s, KTs, K7s-K8s, QJs, Q7s, J7s, T9s, 97s, 64s, 53s, ATo-AJo, A8o, KQo
Always call
QQ+, TT
Mixed
55-99, AJs+, A8s-A9s, A5s, KJs+, Q9s, JTs, J8s, 86s+, 54s, AKo
Settings: 4-max · 100bb · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb (small blind 0.5bb, big blind 1bb, an ante of 0.16bb from every player, 100bb stacks, 5% rake capped at 4.8bb; no rake when no flop is dealt). Solver: HoldemResources Calculator (HRC) (HRC CI 24.66). A jackpot fee on bigger pots is not in this solve, so lines that build big pots may be slightly too loose. Bet sizes are the solved ones; a size that is not here plays like the nearest one.

Fits exactly: no game we have checked.

Close: CoinPoker cash with antes NL50 (rake before the flop in 3-bet pots there, none here).

Rake sources: the ante from 93 of our own CoinPoker hands at $0.25/$0.50 with a $0.08 ante, played 2026-09-30; the caps and the preflop rule from coinpoker.com/games/texas-holdem/, fetched 2026-10-31.