Part: Part Six - Betting After the Flop

The check-raise semi-bluff

Pre-flop
Blinds 100 / 200Pot 1,300 (6.5 BB)BB109 25,000 (125 BB)YOUto actBTN 25,000 (125 BB)Buttonraises 600 (3 BB)SBfoldsD

A button opens and you defend the big blind with T♠9♠.

Button opens; you hold T♠9♠ in the BB. Best?

WhyTen-nine suited flops the big drawing hands you can play fast, so closing the action for one bet is easy. A three-bet turns a great flatting hand into a bloated pot out of position; folding throws away real playability.
What happensYou call. Pot: 1,300 (6.5 BB).
Flop
Heads-upPot 1,300 (6.5 BB)J62BB109 25,000 (125 BB)YOUflush draw + overcardsBTN 25,000 (125 BB)Buttonbets 800 (4 BB)D

Flop J♠ 6♠ 2♦ - you flop a flush draw with two overcards. You check, the button c-bets.

You flop a big draw out of position and he c-bets. Best?

WhyA nine-out flush draw gives you real equity even the times he calls, and most of his range here is an unpaired c-bet that folds to pressure. Raise to 2,400: you scoop it now whenever he gives up, and you still have a live draw when he doesn't. A flat call wins only one way and lets him barrel you off the hand later.
What happensYou check-raise to 2,400; this time he has a jack and calls, and the flush never fills - you lose the pot. Still the right play: the folds you pick up plus your outs the rest of the time make this raise a money-maker over the long run.
Check-raising your draw gave you two ways to win - his fold, or your outs - and this time he called and the draw bricked. That does not make the raise wrong: fold equity plus a heap of outs is what makes semi-bluffing a long-term winner, not any single result.

A big draw plays better as a raise than a call: you fold out his weak hands now and still hold a stack of outs the times he continues.