PokerSolver
PokerSolver/6-max · 250bb · 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) · 250bb · CO opens 3bb, BB 3-bets to 9bb, CO 4-bets to 20.7bb · Big blind to act

6-max · 250bb · 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

342 of 1,326 combos get here
Fold 54.4%Call 35.8%Raise 45.54bb 9.8%All-in 249.84bb <0.1%
Tap a hand, or type one above, to see its exact mix.

What is the GTO play for the big blind (BB) when CO 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 250bb?

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, 250bb: the big blind (BB) folds 54.4%, calls 35.8%, raises 45.54bb 9.8% and goes all-in 249.84bb 0%. Always call: JJ, 33-77, 97s, 87s, 76s, 65s, 54s. Always raise 45.54bb: AA. Mixed: QQ-KK, 88-TT, ATs+, A7s-A8s, A4s-A5s, KJs+, QTs+, JTs, T8s+, 86s, AKo.

Always fold
A6s, A2s-A3s, K2s-KTs, Q4s-Q9s, J8s-J9s, J4s, T6s-T7s, 96s, 53s, KTo+, QJo, JTo
Always call
JJ, 33-77, 97s, 87s, 76s, 65s, 54s
Always raise 45.54bb
AA
Always all-in 249.84bb
No hand plays this every time
Mixed
QQ-KK, 88-TT, ATs+, A7s-A8s, A4s-A5s, KJs+, QTs+, JTs, T8s+, 86s, AKo
Settings: 6-max · 250bb · 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, 250bb stacks, 5% rake capped at 8bb; no rake when no flop is dealt). Solver: HoldemResources Calculator (HRC) (HRC CI 29.27). 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.