Themes WP4 and BP4 (2)

In the next problem-47 we see a double theme BP4.

	(Problem 47) N. G. G. van Dijk, ”American Chess Bulletin”, 1958 White plays and mates in 2 moves #2 (14+7)
[SKb5/Bp1pp3/P1PP1P2/q2k1B1S/R1R1pQ2/2P5/1P6/8]

We observe that there are many tries: {1.Sb6+? Qxb6!}, {1.Sc7+? Qxc7+!}, {1.Bd4? / Bb6? / fxe7? / Sg7? Qb4!}, {1.Bxe4+? Ke6!}, {1.Qd2+? / Qe5+? K(x)e5!}, {1.Qxe4+? Kxd6!}, {1.Rc5+? Qxc5!}, {1.Rd4+? Kxc6!}, {1.Rxa5+? Kxc4!}.
Key: 1.b3!
The meaning of the key-move is to support Rc4 so, if black plays Qa4 or Qb4, the mate Sc7# is valid. The key brings black in a zugzwang situation. Any moves of the BPb7 or of the BPe7 or of any black piece are answered with mate.


In the next problem-48 we watch an WP4-BP4 duel.

	(Problem 48) G. H. Drese, Second Prize, ”Tijdschrift v. d. K. N. S. B.”, 1935 White plays and mates in 3 moves #3 (8+6)
[3S4/4pp2/2RS1B2/KB1k1P2/3p4/4s1s1/5P2/8]

There are a few tries: {1.Rc5+? Kxc5!}, {1.Bc4+? Sxc4+!}, {1.fxe3? exd6!}.
Key: 1.Bd3!
The key brings black in a zugzwang situation. If Se3 moves, there is Bc4#. If Sg3 moves, there is Be4#. The BPe7 tries to defend, but its defenses are voided by the WPf2:
1...e6 2.fxe3 (not 2.fxg3? exf5! and there is no mate).
1...e5 2.fxg3 (not 2.fxe3? dxe3! and Bf6 does not see the flight d4).
1...exd6 2.f3 (protects again the square e4).
1...exf6 2.f4 (protects again the square e5).


[This post in Greek language].