+EV when raising draws?

[bernie]

for the most part, you're right. however, position also helps. you can raise a draw with fewer players in the pot to try for the free card on the turn. making the initial -EV raise on the flop positive since you got a discounted turn.

b

[CORed]

The people you see going 3 or 4 bets with draws with insufficient callers are, for the most part, loose agressive idiots, or at best people who do not fully understand the pricipals of betting or raising a draw for value.

However, there are other reasons to bet or raise a draw.

Semi-bluff: Heads-up or threeway, you are betting (or sometimes raising) because you believe that the total EV from your opponent(s) folding + hitting your draw is positive. This, of course, assumes that your opponents actually fold sometimes, and is best done when opponents appear weak.

Bet instead of call: If you think it is likely that somebody behind you will bet if you check, but it is not likely that someone will raise if you bet, it is often best to bet. The cost is the same, you may win the hand if everyone folds, and it makes it harder for you opponents to read you. This is really a variant of the semi-bluff, but your EV is more on future hands than the current one.

"Free" card raise. In late position in a structured game on the flop, you raise in order to get your opponent(s) to check to you on the turn. This is more correctly a 1/2 price card raise. You put in an extra small bet on the flop to avoid putting in a big bet on the turn. You usually make this play when you are last to act. You can also make it if second to last, if you think it is likely that the last player will fold and leave you last on the turn. Also, if you hit on the turn, less sophisticated players may not think you have the straight or flush, because they don't think you would have raised with a draw.

It is often better to bet a draw rather than check and call, even if the number of anticipated callers isn't quite enough to make a bet for value correct. This is less true if you have agressive players at the table who will frequently raise you, especially if the player to your immediate left will raise and knock out the other players.