PokerSolver
PokerSolver/4-max · 100bb · 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) · 100bb · CO opens 2.5bb, BB 3-bets to 5bb, CO 4-bets to 11.5bb · 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 17.64bbYour cards?
5bb
11.5bb
0.5bb

Tap your two cards.

Big blind's range

284 of 1,326 combos get here
Fold 43.4%Call 47.2%All-in 99.84bb 9.3%
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 100bb?

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, 100bb: the big blind (BB) folds 43.4%, calls 47.2% and goes all-in 99.84bb 9.3%. Always call: TT-JJ, 77-88, 55, AQs, ATs, KQs, JTs, 76s, 65s, 54s, AQo. Mixed: QQ+, AKs, AJs, A8s, A4s-A6s, KTs-KJs, QTs+, J9s, T8s, 98s, AKo.

Always fold
A7s, K8s, Q9s, ATo, KJo+
Always call
TT-JJ, 77-88, 55, AQs, ATs, KQs, JTs, 76s, 65s, 54s, AQo
Always all-in 99.84bb
No hand plays this every time
Mixed
QQ+, AKs, AJs, A8s, A4s-A6s, KTs-KJs, QTs+, J9s, T8s, 98s, 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.