For starters, let’s break down the card. Steam Augury is a 4 mana instant that costs 2UR. Its CMC is the same as one of the most skill intensive cards ever printed: Fact or Fiction, and its similarities to the Extended staple don’t end there. It digs 5 cards deep, the cards get separated into two piles, and one pile gets chosen over the other.
The primary distinction between this and Fact or Fiction is a pretty big deal, however. The caster is the one who makes the piles and the other player is the one who chooses the pile to be given to the caster. This makes getting what you want off a Steam Augury a little tougher than if it were a reprint of Fact or Fiction.
However, the one advantage Steam Augury has is made apparent when multiple cards of the same type are revealed in the five. If digging for lands and there are 2 lands revealed, the opponent will not be able to force you to choose between lands or spells. The same is true for removal spells and threats.
In splitting piles, players will typically want to stack the piles such that one of the important cards are in each of the piles. If there is a card that is overwhelmingly important or just wins the game on the spot in the current boardstate, that card will get put by itself with the other four cards in the other pile. Pretty self-explanatory.
The card is obviously better when you are ahead, when you are not digging for anything specific, and your opponent doesn’t know what you have in hand.
With the return of the Delve mechanic, Steam Augury provides added value. Cards like Treasure Cruise, Empty The Pits, and Dig Through Time come online faster, and 4-1 pile splits become a slightly more reasonable option than they would be otherwise.