Discussion Forum

Think Twice is an Instant so you can leave mana open for responses like Dissipate and then cast it at the end of the opponent's turn.

Also it curves out and allows you to cast it a turn earlier. You don't want to have to tap out turn 3 to draw a few cards because you don't have the answer. However if your a control deck then t2 is usually not a turn you have to worry about disruption. You also want the option of NOT drawing and plaing disruption instead. But if you can get away with not disrupting an opponent then its good to tap mana to draw.

If it was instant speed then it might be played over think twice. But don't get me wrong. Think twice isn't a "good" draw spell if you look at standard historically.