Themes WP4 and BP4 (1)

Theme WP4: A white pawn makes from its starting square four different moves (one step forward, two steps forward, capture left, capture right).

Theme BP4: A black pawn makes from its starting square four different moves (one step forward, two steps forward, capture left, capture right).

	(Problem 41) A. C. Reeves, ”Probleemblad”, 1965 White plays and mates in 2 moves #2 (9+10)
[1s1b1B2/1Q2p3/1p1S1Rp1/S1k5/p3R3/Kp1p4/1sP5/5B2]

In problem-41 there are several tries: {1.Qd5+? Kxd5!}, {1.Qc6+? Sxc6!}, {1.Rf5+? gxf5!}, {1.Sxb3+? axb3!}, {1.Rxa4? exd6!}, {1.Rc4+? Sxc4+!}, {1.Re5+? Kd4!}, but we specifically note that four tries WP4 are answered with four defenses BP4:
Try: {1.c3? [2.Re5#] exf6!}
Try: {1.c4? [2.Qd5#] e6!}
Try: {1.cxb3? [2.b4#] exd6!}
Try: {1.cxd3? [2.d4#] e5!}
Key: 1.Rb4! [2.Se4#]
1...Sc4 2.Rxc4#
1...exd6 2.Bxd6#


In problem-42 black tries to defend with BP4, but white has four continuations with Nowotny intersections.

	(Problem 42) N. Littlewood, First Prize, ”B.C.P.S. Ring Tourney”, 1966 White plays and mates in 3 moves #3 (12+11)
[bb2RSs1/r4p2/qr4PP/p1P1B1k1/3S4/2sP1RpQ/5PK1/8]

There are several tries: {1.Sh7+? Kxg6!}, {1.Bxg3? Bxg3!}, {1.Bf4+? Bxf4!}, {1.Bxb8? Sxh6!}, {1.Qf5+? Kxh6!}, {1.Qg4+? Kxg4!}, {1.Qxg3+? Kh5!}, {1.Qh5+? Kxh5!}, {1.Qh4+? Kxh4!}, {1.fxg3? Rb2+!}.
Key: 1.Re6! ( > 2 Sh7#)
1...f6 2.Rd6 (Nowotny on d6) Rxd6 / Bxd6 3.Bf4# / Sde6#
1...f5 2.Rc6 (Nowotny on c6) Rxc6 / Bxc6 3.Rxg3# / Sde6#
1...fxe6 2.c6 (Nowotny on c6) Rxc6 / Bxc6 3.Rxg3# / Sde6#
1...fxg6 2.Bc7 (Nowotny on c7) Rxc7 / Bxc7 3.Re5# / Sh7#


In problem-43 we see that the mates for BP4 are changed in two phases.

	(Problem 43) A. C. Reeves, ”Die Schwalbe”, 1965 (Set play). White plays and mates in 2 moves * #2 (13+6)
[R2Sr3/RB1pk1P1/PpP1P1P1/1K2p1P1/3Q4/2Sr4/8/8]

First Phase: (*) (Set play)
1...d6 / d5 / dxc6+ / dxe6
2.Sd5# / Qb4# / Bxc6# / Bc8#

If we start with checks, we do not achieve our goal:
Tries: {1.Qb4+? d6!}, {1.Qxd7+? Rxd7!}, {1.Sd5+? Kd6!}

Last Phase: Key: 1.Qxe5!
1...d6 / d5 / dxc6+ / dxe6
2.Qf6# / Qc7# / Sxc6# / Qxe6# (four mates are changed).


In the problem-44 the King Kf6 with the Bishop Bg7 form a royal battery which fires with a move of Kf6.

	(Problem 44) Henry D’ Oyly Bernard, Second Prize ex aequo, ”Good Companions”, 1917 (Set play). White plays and mates in 2 moves * #2 (14+10)
[2s3b1/6B1/p3PKP1/p1pp1R2/QbPk1pr1/4sP2/1PPS1P2/3R4]

First Phase: (*) (set play)
1...Bb~ (makes a random move) / Bxd2 2.Sb3# / Rxd2#

There are many tries : {1.Bh8? Rh4!}, {1.Rxf4+? Rxf4+!}, {1.Rxd5+? Sxd5+!}, {1.Qb3? dxc4!}, {1.Qb5? axb5!}, {1.Qa3? Bxa3!}, {1.Qxb4? cxb4!}, {1.fxg4? Sxg4+!}, {1.fxe3+? Kxe3!}, {1.Sb1+? Sxd1!}, {1.Se4+? Sxd1!}, {1.Sb3+? Kxc4!}, {1.c3+? Kd3!}.

Last Phase: Key: 1.Qa1!
The key brings black in zugzwang situation, despite the fact that black has many available moves. The four moves of Bb4 are handled by the wPb2.
1...Ba3 / Bxd2 / Bc3 / Bxa5
2.bxa3# / b3# / bxc3# / b4#
[This post in Greek language].