Following is an example which is taken from a master game. As far
as the material is concerned the players are about even, as the
Queen is worth as much as the two Rooks while Knight and Bishop
are an approximate equivalent of the Black Rook and the Pawn
which Black is ahead. The Pawn a4 is rather dangerous for White,
as he needs only three more moves to reach the first rank where
he can be promoted into any piece. On the other hand the Rooks
doubled in the seventh rank give White so strong an attack on the
Black King that he forces the mate before Black succeeds in
realizing the advantage of his advanced passed Pawn.

+---------------------------------------+
8 | | | | | #R | #K | | |
|---------------------------------------|
7 | | #P | ^R | ^R | | #P | #P | #P |
|---------------------------------------|
6 | | | | | | | | |
|---------------------------------------|
5 | | | | | | | | |
|---------------------------------------|
4 | #P | | | | ^P | ^Kt| | |
|---------------------------------------|
3 | | | | | | | ^P | ^B |
|---------------------------------------|
2 | #Q | | | | | ^P | | ^P |
|---------------------------------------|
1 | | | | | | | ^K | |
+---------------------------------------+
a b c d e f g h