9♠9♦ BB vs BTN, river on K♦ 8♠ 4♥ 3♦ A♣, 100 bb
The spot
- You: BB
- Opponent: BTN
- Your hand: 9♠9♦
- Board: K♦ 8♠ 4♥ 3♦ A♣
- Effective stack: 100 bb
- Pot: 21.5 bb
River checks to hero after two-street sequence.
Best river decision in baseline?
See the answer
Best play: Check
Why
Final board K♦8♠4♥3♦A♣: the river A means BTN's value is A-x and K-x plus the odd set/two pair, while busted diamond and straight draws form his air. Hero's 9♠9♦ is an underpair to both the A and the K — it beats only missed draws and smaller pairs, never the top pairs that continued. Out of position a 40% "thin value" lead is dominated: the only callers are the air you already beat, and every K-x/A-x calls and beats you, so checking to bluff‑catch is the cleaner OOP line.
Key idea
An underpair to the board's high cards only beats air: check OOP and bluff‑catch, don't bet it for value.
Common mistake
Thin-value betting an underpair — worse hands fold and every top pair calls and wins.