(Cuddalore, Tamilnadu, India)
Q. How do you decide what piece soldier promotes to? Do soldiers promote to different pieces depending on what file they promote? What will happen when my soldier occupies the opponent place of horse?A.
When a pawn reaches the final rank in the knight's file (or any other file), it can promote to any back row piece apart from a king. In other variants the file is significant, the pawn would promote to a bishop in a bishop file or a knight in a knight file and so on. But not so in Western Chess. A queen is usually requested. Otherwise it is referred to as under-promotion when a knight, bishop or rook is requested. Further reading is available on pawn promotion