MESON Chess Problem Database

Problem Display
PID: 538 (2Qb4/pn1p4/Rp1pk1NN/1KP1P3/2r4B/4PP2/B7/8 w - - 0 1)

Ling, John Francis

The Observer, 1961

2Qb4/pn1p4/Rp1pk1NN/1KP1P3/2r4B/4PP2/B7/8

#2

11 + 8

SOLUTION

  • SOUND
  • Sets
    • 1...Kd5
      • 2.Bxc4#
    • 1...Bxh4
      • 2.Qg8#
    • 1...Bg5
      • 2.Qg8#
    • 1...Bf6
      • 2.Qg8#
    • 1...Bc7
      • 2.Qg8#
    • 1...Be7
      • 2.Qg8#
    • 1...bxc5
      • 2.Bxc4#
    • 1...dxc5
      • 2.Bxc4#
    • 1...dxe5
      • 2.Bxc4#
  • Tries
    • 1.Bf6?
      • threat
        • 2.Sf4#
      • 1...Kd5
        • 2.Sf4#
        • 2.Bxc4#
      • 1...Bxf6
        • 2.Qg8#
      • 1...d5
        • 2.Sf8#
      • 1...dxe5!
    • 1.Qxd7+?
      • 1...Kd5
        • 2.Bxc4#
        • 2.Qf7#
      • 1...Kxd7!
    • 1.Qc6?
      • threat
        • 2.Bxc4#
      • 1...Sa5
        • 2.Qxd6#
      • 1...dxc6+!
    • 1.Qxd8?
      • threat
        • 2.Qg8#
      • 1...Kd5
        • 2.Bxc4#
        • 2.Qg8#
      • 1...Sxd8!
  • Keys
    • 1.Qb8!
      • 1...Kd5
        • 2.Bxc4#
      • 1...Bxh4
        • 2.Qg8#
      • 1...Sxc5
        • 2.Qxd6#
      • 1...bxc5
        • 2.Bxc4#
      • 1...dxc5
        • 2.Sf4#
      • 1...dxe5
        • 2.Qxe5#
      • 1...Sa5
        • 2.Qxd6#
      • 1...Bg5
        • 2.Qg8#
      • 1...Bf6
        • 2.Qg8#
      • 1...Bc7
        • 2.Qg8#
      • 1...Be7
        • 2.Qg8#
      • 1...d5
        • 2.Sf8#

FEATURES

  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 2
    • ADDED MATES = 3
    • REMOVED MATES = 0
  • Sets
    • K(d);N_SPINP(g),S_FLIGHT::B(A),XR(a)
    • B(h);OGATE,XB(D)::QAB(K)
    • B(h);OGATE::QAB(K)
    • P(b);N_SPINP(g),P_SPINP(c),XP(F)::B(A),XR(a)
    • P(c);N_GUARD,N_SPINP(g),P_SPINP(b),XP(F)::B(A),XR(a)
    • P(c);N_GUARD,N_SPINP(g),P_SPINP(b),XP(G)::B(A),XR(a)
  • Tries
    • Try
      • B(D);
      • Threat
        • S(I)
      • Vars
        • B(h);OGATE,XB(D)::QAB(K)
        • P(c);N_SPINP(g),N_SPINR(a),P_SPINP(b),SBLOCK::S(I)
      • Refutation
        • P(c);N_SPINP(g),P_SPINP(b),XP(G)
    • Try
      • Q(K);CHECK,XP(g)
      • Refutation
        • K(d);N_SPINR(a),S_FLIGHT,XQ(K)
    • Try
      • Q(K);N_PINP(g),P_PINP(c)
      • Threat
        • B(A),XR(a)
      • Vars
        • S(f);N_GUARD::QAR1(K),XP(c)
      • Refutation
        • P(g);CHECK,N_SPINP(c),XQ(K)
    • Try
      • Q(K);N_PINP(g),XB(h)
      • Threat
        • QAB(K)
      • Refutation
        • S(f);XQ(K)
  • Actual
    • Q(K);N_PINP(g)
    • Vars
      • K(d);S_FLIGHT::B(A),XR(a)
      • B(h);OGATE,XB(D)::QAB(K)
      • S(f);N_GUARD,XP(F)::QAR1(K),XP(c)
      • P(b);P_SPINP(c),XP(F)::B(A),XR(a)
      • P(c);P_SPINP(b),XP(F)::S(I)
      • P(c);OGATE,P_SPINP(b),XP(G)::QAR1(K),XP(c)
      • S(f);N_GUARD::QAR1(K),XP(c)
      • B(h);OGATE::QAB(K)
      • P(c);N_SPINR(a),P_SPINP(b),SBLOCK::S(I)
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