conditions. Problems may be divided into two classes:
(1) Direct mate, in which White moving first has to force a checkmate in a given number of moves, generally two, three, or four.
(2) Suimate, in which White, playing first, has to force Black to checkmate him in a given number of moves.
Problems involving other conditions are known as puzzles.
Protect. To guard or support a Piece by the interposition of another force between the Piece attacked and the attacking Piece. A superior force is protected or covered from attack by an inferior one.
Queening a Pawn or Advancing a Pawn to Queen. When a player has advanced a Pawn to the eighth, or last, square of a file, it assumes the rank and power of a Queen or any other Piece, excepting a King, that the player chooses, in which case he is said to have Queened a Pawn.
Ranks. The horizontal rows of squares across the board, from one side to the
