MESON Chess Problem Database

Problem Display
PID: 153931 (8/1rPk4/B2PR3/B2RK3/8/8/8/8 w - - 0 1)

Harley, Brian

The Observer, 1951

(First published on Sun Sep 2 1951)

8/1rPk4/B2PR3/B2RK3/8/8/8/8

#2

7 + 2

15290 Harley Scrapbook 2015
15239 Valois Notebooks 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Kc6
      • 2.d7#
    • 1...Kc8
      • 2.d7#
    • 1...Rb1
      • 2.c8Q#
    • 1...Rb2
      • 2.c8Q#
    • 1...Rb3
      • 2.c8Q#
    • 1...Rb4
      • 2.c8Q#
    • 1...Rb5
      • 2.c8Q#
    • 1...Rb6
      • 2.c8Q#
    • 1...Ra7
      • 2.c8Q#
    • 1...Rxc7
      • 2.dxc7#
    • 1...Rb8
      • 2.cxb8S#
  • Tries
    • 1.Kf5?
      • 1...Kc8
        • 2.d7#
      • 1...Rxc7
        • 2.dxc7#
      • 1...Rb1
        • 2.c8Q#
      • 1...Rb2
        • 2.c8Q#
      • 1...Rb3
        • 2.c8Q#
      • 1...Rb4
        • 2.c8Q#
      • 1...Rb5
        • 2.c8Q#
      • 1...Rb6
        • 2.c8Q#
      • 1...Ra7
        • 2.c8Q#
      • 1...Rb8
        • 2.cxb8S#
      • 1...Kc6!
    • 1.Kf6?
      • 1...Kc8
        • 2.d7#
      • 1...Rxc7
        • 2.dxc7#
      • 1...Rb1
        • 2.c8Q#
      • 1...Rb2
        • 2.c8Q#
      • 1...Rb3
        • 2.c8Q#
      • 1...Rb4
        • 2.c8Q#
      • 1...Rb5
        • 2.c8Q#
      • 1...Rb6
        • 2.c8Q#
      • 1...Ra7
        • 2.c8Q#
      • 1...Rb8
        • 2.cxb8S#
      • 1...Kc6!
    • 1.Bb5+?
      • 1...Kc8
        • 2.Re8#
        • 2.d7#
      • 1...Rxb5!
    • 1.Re7+?
      • 1...Kc8
        • 2.d7#
      • 1...Kc6!
    • 1.c8B+?
      • 1...Kc6
        • 2.Baxb7#
        • 2.d7#
      • 1...Kxc8!
    • 1.c8R?
      • 1...Rb1
        • 2.Re7#
      • 1...Rb2
        • 2.Re7#
      • 1...Rb3
        • 2.Re7#
      • 1...Rb4
        • 2.Re7#
      • 1...Rb5
        • 2.Re7#
      • 1...Rb6
        • 2.Re7#
      • 1...Ra7
        • 2.Re7#
      • 1...Rc7
        • 2.dxc7#
      • 1...Rb8
        • 2.Re7#
      • 1...Kxc8!
  • Keys
    • 1.Bb6!
      • 1...Kc6
        • 2.d7#
      • 1...Kc8
        • 2.d7#
      • 1...Rxb6
        • 2.c8Q#
      • 1...Rxc7
        • 2.dxc7#
      • 1...Ra7
        • 2.c8Q#
      • 1...Rb8
        • 2.cxb8S#

FEATURES

  • Static
    • TYPE = WAITER
    • CHANGED MATES = 0
    • ADDED MATES = 0
    • REMOVED MATES = 5
  • Sets
    • K(b);OGATE,S_FLIGHT::R(F)+P(E)
    • K(b);OGATE,P_SPINR(a),S_FLIGHT::P(E)
    • R(a);::P=Q
    • R(a);P_PINR(B)::P=Q
    • R(a);OGATE,XP(G)::R(B)+P(E),XR(a)
    • R(a);OGATE::PXR(a)=S
  • Tries
    • Try
      • K(C);P-FLIGHT
      • Vars
        • K(b);OGATE,P_SPINR(a),S_FLIGHT::P(E)
        • R(a);OGATE,XP(G)::R(B)+P(E),XR(a)
        • R(a);::P=Q
        • R(a);P_PINR(B)::P=Q
        • R(a);OGATE::PXR(a)=S
      • Refutation
        • K(b);S_FLIGHT
    • Try
      • K(C);S_FLIGHT
      • Vars
        • K(b);OGATE,P_SPINR(a),S_FLIGHT::P(E)
        • R(a);OGATE,XP(G)::R(B)+P(E),XR(a)
        • R(a);::P=Q
        • R(a);OGATE::PXR(a)=S
      • Refutation
        • K(b);S_FLIGHT
    • Try
      • B(D);CHECK
      • Refutation
        • R(a);P_PINR(B),XB(D)
    • Try
      • R(F);CHECK
      • Vars
        • K(b);OGATE,P_SPINR(a),S_FLIGHT::P(E)
      • Refutation
        • K(b);S_FLIGHT
    • Try
      • P(G);CHECK
      • Refutation
        • K(b);P_SPINR(a),S_FLIGHT,XB(G)
    • Try
      • P(G);
      • Vars
        • R(a);::R1(F)
        • R(a);P_PINR(B)::R1(F)
        • R(a);OGATE::R(B)+P(E),XR(a)
      • Refutation
        • K(b);P_SPINR(a),S_FLIGHT,XR(G)
  • Actual
    • B(A);
    • Vars
      • K(b);OGATE,S_FLIGHT::R(F)+P(E)
      • K(b);OGATE,P_SPINR(a),S_FLIGHT::P(E)
      • R(a);XB(A)::P=Q
      • R(a);OGATE,XP(G)::R(B)+P(E),XR(a)
      • R(a);::P=Q
      • R(a);OGATE::PXR(a)=S
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