PokerSolver
PokerSolver/6-max · 80bb · SB 0.5bb · ante 0.16bb · 5% rake, cap 8bb/BB vs CO 4-bet 20.7bb

BB vs CO 4-bet 20.7bb

6-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 8bb (blinds 0.5/1bb, ante 0.16bb) · 80bb · CO opens 3bb, BB 3-bets to 9bb, CO 4-bets to 20.7bb · Big blind to act

6-max · 80bb · SB 0.5bb · ante 0.16bb · 5% rake, cap 8bbChange game
Stacks (bb), if they differ
Pot 31.16bbYour cards?
9bb
20.7bb
0.5bb

Tap your two cards.

Big blind's range

426 of 1,326 combos get here
Fold 73%Call 7.6%All-in 79.84bb 19.4%
Tap a hand, or type one above, to see its exact mix.

What is the GTO play for the big blind (BB) when CO opens 3bb, BB 3-bets to 9bb, CO 4-bets to 20.7bb in 6-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 8bb at 80bb?

CO opens 3bb, BB 3-bets to 9bb, CO 4-bets to 20.7bb in 6-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 8bb, 80bb: the big blind (BB) folds 73%, calls 7.6% and goes all-in 79.84bb 19.4%. Always call: AJs, A8s, JTs, 65s. Always all-in 79.84bb: TT+, 77, 55, AKs, A5s, QJs, AKo. Mixed: 88, 66, AQs, A4s, KQs, T9s, 87s, 76s, 54s.

Always fold
A6s, A2s-A3s, K2s-K8s, Q8s, Q4s-Q6s, J3s-J8s, T6s-T8s, 85s-86s, 75s, 63s, 43s, AQo, A5o-A8o, K8o+, J9o+, T9o
Always call
AJs, A8s, JTs, 65s
Always all-in 79.84bb
TT+, 77, 55, AKs, A5s, QJs, AKo
Mixed
88, 66, AQs, A4s, KQs, T9s, 87s, 76s, 54s
Settings: 6-max · 80bb · SB 0.5bb · ante 0.16bb · 5% rake, cap 8bb (small blind 0.5bb, big blind 1bb, an ante of 0.16bb from every player, 80bb stacks, 5% rake capped at 8bb; no rake when no flop is dealt). Solver: HoldemResources Calculator (HRC) (HRC CI 24.92). 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.