PokerStars No-Limit Hold'em, $0.10 BB (5 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

Hero (BB) ($10.65)
UTG ($17.70)
MP ($9.85)
Button ($11.30)
SB ($9.30)

Preflop: Hero is BB with K, 4
3 folds, SB calls $0.05, Hero checks

Flop: ($0.20) 5, 3, 7 (2 players)
SB checks, Hero checks

Turn: ($0.20) 10 (2 players)
SB checks, Hero checks

River: ($0.20) 6 (2 players)
SB checks, Hero bets $0.40, 1 fold

Total pot: $0.20 | Rake: $0


HOW do you bet this river? Such a tough spot.