ChessNonStop
Why a Queen is Not Always the Best Choice
From Good to Great: Pro-Level Tips
The Knight Promotion Checkmate
The most common reason to underpromote is to promote to a knight. A new knight can deliver an immediate, often unexpected, check or fork that would be impossible for a queen. Always check for knight moves when your pawn is on the 7th rank.
Avoiding Stalemate
The second most common reason is to avoid stalemate. If promoting to a queen would remove all legal moves for the opponent's king (without putting it in check), the game is a draw. Promoting to a rook instead can keep the game going and secure the win.
A Move That Made History: The Saavedra Position
The Saavedra position is arguably the most famous endgame study involving underpromotion. White must stop the black pawn from promoting. It seems Black can force a draw by queening and checking. However, the solution involves a stunning underpromotion to a rook! After a series of precise moves, White forces Black to promote, then skewers the new queen against the king. Black's only way to avoid this is to underpromote to a rook, leading to a drawn rook endgame. It is a multi-layered and beautiful piece of chess art.
The Winning Combination: 1. Kb2 a1=Q+ 2. Kxa1 Kb5 3. Kb2