The position of Diagram 39 is somewhat related to that of Diagram 38, as far as the possibility of a sacrifice for the sake of a pin is concerned. If White plays B-b5+ Black must not interpose his Bishop, for White will give up his Rook for the Bishop in order to force the Rook d8 into a pinned position and then he will win the Rook by R-d1.
+———————————————————-+
8 | | | | #R | #K | | | #R |
|———————————————————-|
7 | #P | #P | | | | #P | #P | #P |
|———————————————————-|
6 | | | | | #B | | | |
|———————————————————-|
5 | | | | | #P | | | |
|———————————————————-|
4 | | | | | ^P | | | |
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3 | | | | | | | | |
|———————————————————-|
2 | ^P | ^P | ^P | | | | ^P | ^P |
|———————————————————-|
1 | | | ^K | ^R | | ^B | | ^R |
+———————————————————-+
a b c d e f g h
DIAGRAM 39.
In the position of Diagram 40 there is also a possibility of a sacrifice with the view to pin a piece that defends a certain threat as long as it is mobile. White plays (1) Q-d5, and Black dares not take White's Knight with his Queen for White would continue (2) Qxf7+, Rxf7; (3) R-e8+/-.
What Black could try is (1) Kt-h6.
+———————————————————-+
8 | #R | | #B | #Q | | #R | #K | |
|———————————————————-|
7 | #P | #P | | #P | | #P | #P | #P |
|———————————————————-|
6 | | | | #P | | | | |
|———————————————————-|
5 | | | | | | #Kt| ^Kt| |
|———————————————————-|
4 | | | ^B | | ^R | | | |
|———————————————————-|
3 | | | | | | | | |
|———————————————————-|
2 | ^P | ^P | | | | ^P | ^P | ^P |
|———————————————————-|
1 | ^R | | | ^Q | | | ^K | |
+———————————————————-+
a b c d e f g h
DIAGRAM 40.
The Pawn f7 would then be three times attacked and three times protected so that White cannot take him as now the pin of the Rook resulting from Ktxf7, Ktxf7; Qxf7, Rxf7 does not lead to anything, the square e8 being protected by the Queen. However, White can force the win by (2) Ra1- e1, threatening again the sacrifice of f7, as he now controls the square e8 twice. If Black replies (2) …, Q-f6, protecting f7 for the fourth time and thereby making impossible White's sacrifice on that point, White continues with (3) R-e8. This threatens Rxf8+, Kxf8; Ktxh7+ winning the Queen. Black cannot defend himself with Q-g6 on account of (4) B-d3 followed by Bxh7+ and Rxf8, etc., nor can he play (3) …, Q-f4 on account of P-g3 followed by Qxd6, attacking the defenseless Rook f8.
A sacrifice with the view to enabling a mating attack through the cooperation of Rooks and Bishop somewhat similar to the examples discussed in the previous chapter is possible in the position of Diagram 41 which occurred in a Tournament game in London in which the author conducted the black men.
Black's combination starts with the sacrifice of the Queen on f3. After (1) …, Qxf3; (2) Pxf3, B-h3+; (3) K-g1 White's King is held in an immobile position by the Black Bishop and a check with one of Black's Rooks in the g-file would be deadly.