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Which material can mate
Not every advantage is enough.
To force mate you must control enough squares to trap the king at the edge. A queen, a rook, or two bishops can do it. A single bishop or a single knight cannot — there just aren't enough squares covered, so the king always slips away and the game is a draw.
In the diagram, White has a lone bishop. No matter how perfectly White plays, the bishop and king can never corner a lone king. Keep this in mind when simplifying: trade down to a rook, a queen, or a pawn that can promote — not to a single minor piece.
King and ONE bishop versus a lone king. With best play, the result is:
Answer the question to keep going!