A♦9♣ BB vs SB, preflop, 85 bb
The spot
- You: BB
- Opponent: SB
- Your hand: A♦9♣
- Board: preflop, no board yet
- Effective stack: 85 bb
- Pot: 6.5 bb
Villain opens and action is on hero preflop.
Which action keeps the best EV baseline?
See the answer
Best play: Call
Why
BB facing an SB open with A9 offsuit (A of diamonds, 9 of clubs). The SB opens an extremely wide range, so BB defends a huge portion of hands. A9o is comfortably ahead of the SB opening range and is a clear continue: getting a good price closed-action, you call to realize ace-high and top-pair equity in position-neutral but capped-pot conditions. A small mix of 3‑bets exists for value/blocker reasons, but flatting is the highest-EV baseline because it keeps the SB s dominated weaker aces and offsuit junk in the pot. Folding A9o here would be far too tight given the SB s wide range and the BB s pot odds.
Key idea
Vs an SB open the BB defends extremely wide. A9o is a clear flat: it dominates much of the SB s wide range and gets a great price to realize ace-high equity.
Common mistake
Over-folding A9o in the BB versus a wide SB open, or auto-3-betting it. Flatting captures the most EV by keeping the SB s dominated aces and junk in the pot.