Sift

In Commander, Sift sits at the bottom of the draw-spell pecking order — four mana at sorcery speed for a net of two cards is a weak rate when the format's staples like Fact or Fiction and Ponder exist at lower costs. The discard clause redeems it only in graveyard-centric decks where pitching a card is a benefit, not a tax. In Pauper, the common card pool is thinner, so Sift sees occasional play as filler draw in slower controlling shells, though Accumulated Knowledge and Preordain are strictly better options. Legacy, Modern, Vintage, and Pioneer have no interest in it — the efficiency bar in those formats is far higher than Sift can clear.