While in many betting trick-taking games, the players announce how many tricks they will win, in Seven Prophecies, the players must announce how many times they will come 1st, 2nd, and other places, like coming 1st twice, 2nd once, 3rd once, and 4th three times.
Does it sound too difficult? Not at all!
Because you "know the future!"
Before you start the game, you know the lead suits of all the tricks (what color cards to be played), so compare them with your hand and announce with which cards you're likely to win.
However, note that other players can also predict the future and thus have acquired the same information. Try to also read other players' thoughts and predict which places you will come.