Glimpse the Future
The trade is cleaner than most card-advantage spells admit: three mana buys exactly one card, and the price for seeing your top three is that the two you reject hit the graveyard rather than returning to the deck. That destination is the entire point. A version that buried the unwanted cards on the bottom of your library would be strictly safer and strictly weaker; sending them to the yard makes every cast a deliberate self-mill, a feature for any deck that wants cards there: flashback, delve, reanimation, escape, threshold. Among the long line of blue dig spells, this one threads a specific niche between pure smoothing and pure fueling. It refills your hand by one while loading your graveyard by two, and a deck that treats the bin as a resource rather than a dead zone collects on both ends. Hold it next to older filtering spells that simply replace themselves: there the surplus cards are waste, here they are deposits. The constraint that earns the symmetry is that you only ever keep one of the three, so the casting decision is really a question of which graveyard you are building. The builder who has already decided what the bin is for gets the rate that everyone else is paying for and throwing away.
