The free card play is most effective in passive online poker games. The premise of the play is that your opponents will behave in predictable and passive way if you raise the flop. The more likely your opponents are to just call your raise and to check to you the turn, the more frequently you should attempt a free card play.
For instance, if you could be totally certain that your free card play would succeed (your opponents will always just call you r flop raise and check the turn), you should raise virtually every time you have a draw that you would call with. If your draw is worth seeing one card for one small bet, it is almost always worth seeing two cards for two small bets.65
As the online poker game gets more aggressive, you should become more selective with your free card attempts. When you raise for a free card, you risk being re-raised, or called, and then bet into on the turn. With strong draws like flush draws and quality open-ended straight draws, this prospect should not concern you. Since these draws come in so often, you can often raise them for value; getting a free card on the turn is just a bonus. But when you hold a weak draw like bottom pair or a gut-shot, you cannot raise with impunity. You must weigh the chance that your play will succeed against the chance that it will backfire. Paying three bets to see the turn when you could have paid only one is expensive. Even paying two bets on the flop is bad if someone calls, but bets into you on the turn.
Against passive players feel free to try free card plays with these weak draws. Your opponents will check the turn often 65 There is a minor exception that involves hands with backdoor draws. With these hands you can be drawing live on the flop, but drawing dead on the turn most of the time (when you do not pick up your draw). For a backdoor draw, seeing fourth street is more valuable than seeing fifth street, so with a weak enough hand, you might want to see the turn for one bet, but not the turn and river for two bets.