Q♠J♠ SB vs BTN, turn on Q♣ 8♦ 4♠ 2♠, 55 bb

Best play: Bet 40% pot

Why

Turn (four cards) on Q-club 8‑4-spade-2-spade, SB out of position leading into a capped BTN. Hero's Q-s-J-s is top pair, J kicker, plus the nut-tier spade flush draw (Q-spade gives the top of the flush, and two board spades complete it on any spade river). A small 40% lead merges thin value from worse Q-x and protects/charges the many draws and overcards while keeping the pot manageable as the out-of-position player; equity is still very live so a polar overbet is unnecessary.

Key idea

On the turn, top pair plus a nut-flush draw is a strong but still-developing hand — a small merged lead is fine because you have both showdown value and equity to protect, not a polar all-or-nothing holding.

Common mistake

Confusing the made flush with a flush draw, or overbetting the turn and bloating the pot out of position with a one-pair-plus-draw hand that prefers a controlled size.