PokerSolver
PokerSolver/4-max · 80bb · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb/BB vs CO 4-bet 11.5bb

BB vs CO 4-bet 11.5bb

4-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb (blinds 0.5/1bb, ante 0.16bb) · 80bb · CO opens 2.5bb, BB 3-bets to 5bb, CO 4-bets to 11.5bb · Big blind to act

4-max · 80bb · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bbChange game
Stacks (bb), if they differ
Pot 17.64bbYour cards?
5bb
11.5bb
0.5bb

Tap your two cards.

Big blind's range

246 of 1,326 combos get here
Fold 43.9%Call 45.9%All-in 79.84bb 10.2%
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 2.5bb, BB 3-bets to 5bb, CO 4-bets to 11.5bb in 4-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb at 80bb?

CO opens 2.5bb, BB 3-bets to 5bb, CO 4-bets to 11.5bb in 4-max · SB 0.5bb · ante 0.16bb · 5% rake, cap 4.8bb, 80bb: the big blind (BB) folds 43.9%, calls 45.9% and goes all-in 79.84bb 10.2%. Always call: TT-QQ, 55-88, ATs-AQs, KTs-KJs, 75s+, 65s, AQo. Always all-in 79.84bb: AA. Mixed: KK, A3s-A5s, K7s, QJs, JTs, T9s, AKo.

Always fold
A8o, KQo, QJo
Always call
TT-QQ, 55-88, ATs-AQs, KTs-KJs, 75s+, 65s, AQo
Always all-in 79.84bb
AA
Mixed
KK, A3s-A5s, K7s, QJs, JTs, T9s, AKo
Settings: 4-max · 80bb · 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, 80bb stacks, 5% rake capped at 4.8bb; no rake when no flop is dealt). Solver: HoldemResources Calculator (HRC) (HRC CI 24.98). 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.