Piece values in chess are a point system used to quickly assess the material balance between the two sides. Each piece type is assigned a conventional value: a pawn is worth 1 point, a knight and a bishop are each worth approximately 3 points, a rook is worth 5 points, and the queen is worth 9 points. The king has no numerical value, as losing it ends the game.
These values are statistical averages drawn from millions of games: they reflect the general power of each piece, but not necessarily its worth in a specific position. A knight stuck on the edge of the board, for instance, may be worth far less than 3 points in practice, while a passed pawn (one with no opposing pawn on its file or adjacent files) close to promotion can be worth considerably more.
In practice, this point system is your first tool for evaluating exchanges: if you capture an opponent’s rook with your knight, you gain 2 points of material (5 − 3), which is called "winning the exchange." Before capturing or accepting a sacrifice, get into the habit of doing this quick mental calculation to avoid unintentional material loss.
