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

DIAGRAM 22.

Sometimes two pieces are involved in the double attack, the line
of one of the pieces being discovered by the other. Thus, in the
position of Diagram 22, which could be brought about by the moves
(1) P-e4, P-d5; (2) Pxd5, Qxd5; (3) Kt-c3, Q-a5; (4) P-d4, Kt-f6;
(5) B-c4, P-e6; (6) B-d2, white threatens to play (7) Kt-d5,
uncovering the Bishop d2 on Black's Queen and at the same time
attacking the Pawn c7, which Black cannot keep protected.

Threats of this kind more frequently occur in connection with a
discovered Check. As an example the following opening will serve: