A common sort of position. You might begin by seeing that moving the knight on f3 to e5 creates an almost-fork: it attacks the Black bishop on g4, and a pawn that is next to the Black king. The next thought is to wonder if the king could be moved onto the f7 square by taking the pawn. White has a resource for the purpose in Bxf7+. (You might have reached this same juncture more conventionally by just examining any check you might be able to give, and finding only Bxf7+.) Black can reply to Bxf7+ with either KxB or Kd7. Then what? Redo the color scan: now White’s f3 knight, Black’s g4 bishop, and Black’s king all are on light squares. Ne5+ forks bishop and king. Notice that Black had thought the White knight was pinned to White’s queen, but since Ne5 is a check Black has no time to take advantage of this; he has to move the king, and then loses the bishop. Another point to note: the bishop is protected by the Black knight at f6. Do you care? No, because after Ne5 the bishop also is attacked a second time by White’s queen; so if Black recaptures with NxN, White plays QxN and still is ahead a pawn. The question is not just whether a piece is protected; it’s always how many times it is protected compared to how many times it is under attack.