Algebraic notation (chess) board. Thus each square has a unique identification of file letter followed by rank number. (For example, White's king starts the game on square e1; Black's knight on b8 can move to open squares a6 or c6.) Each piece type (other than pawns) is identified by an uppercase letter. English-speaking players use the letters "K" for king, "Q" for queen, "R" for rook, "B" for bishop, and "N" for knight (since K is already used). "S" (from the German "Springer") was also used for the knight in the early days of algebraic notation and is still used in some chess
Progressive chess move number (leading to notation in progressive chess like 1.e4 2.e5 Nf6 3.Bc4 Qh5 Qxf7#). In this way, the move number is equal to the number of moves in a series available to a player on that turn. There is another form of progressive chess, English progressive chess, which makes quite a significant change to the rules: within each turn, no piece may be moved twice until every other piece which has a legal move has moved once; no piece may move three times until every other piece which can has moved twice; and so on. These restrictions do not