Or not. In general I strongly believe that you need to trust you instincts when you are playing poker. If you make a bet and someone calls you may think to yourself, they are on a flush draw. The turn brings the flush card, as it is want to do, and both players check. A river blank and your opponent bets. Are you willing to call that bet? In general you need to trust your first thoughts. If you think that someone is drawing, don’t be dissuaded just because they didn’t play aggressively when the draw hit. And don’t think to yourself, if I hit the draw I would bet, because all players don’t play like you. However if you strongly believe that a bet is a bluff, and you are not just trying to rationalize to yourself a reason to call then by all means do it.

Now on to when you shouldn’t trust your instincts. Never play cards or make a loose call just because you think that you can predict which cards will hit. Trust me, you can’t. Those cards are governed by random statistics, and assuming you haven’t marked them, you don’t know the cards that are about to come. If you still believe that you can predict the cards then I invite you to take up this challenge http://www.randi.org/research/ they offer $1,000,000 to anyone who can prove that they have paranormal powers, and I’m sure they will accept your card predicting ability as a claim.