MESON Chess Problem Database

Problem Display
PID: 154124 (4k3/1N1Nqp2/8/1PB5/K2Qp3/8/8/8 w - - 0 1)

Harley, Brian

The Observer, 1954

(First published on Sun Sep 5 1954)

4k3/1N1Nqp2/8/1PB5/K2Qp3/8/8/8

#2

6 + 4

15290 Harley Scrapbook 2015
15239 Valois Notebooks 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Qf6
      • 2.Sxf6#
    • 1...Qf8
      • 2.Sf6#
    • 1...Qxd7
      • 2.Qh8#
  • Tries
    • 1.Qh8+?
      • 1...Qf8
        • 2.Sf6#
      • 1...Kxd7!
    • 1.Qxe4?
      • threat
        • 2.Qxe7#
      • 1...Kxd7
        • 2.Qc6#
      • 1...Qe5
        • 2.Sf6#
      • 1...Qe6
        • 2.Sf6#
      • 1...Qxe4+!
  • Keys
    • 1.Qf6!
      • threat
        • 2.Qxe7#
      • 1...Kxd7
        • 2.Qc6#
      • 1...Qxc5
        • 2.Qd8#
      • 1...Qxf6
        • 2.Sxf6#
      • 1...Qxd7
        • 2.Qh8#
      • 1...Qd6
        • 2.Qd8#
      • 1...Qd8
        • 2.Qxd8#
      • 1...Qf8
        • 2.Qd8#
      • 1...Qe5
        • 2.Qd8#
      • 1...Qe6
        • 2.Qd8#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 6
    • REMOVED MATES = 0
  • Sets
    • Q(b);N_GUARD::S(F),XQ(b)
    • Q(b);N_GUARD::S(F)
    • Q(b);N_GUARD,P_PINP(C),SBLOCK,XS(F)::QAR(B)
  • Tries
    • Try
      • Q(B);CHECK
      • Vars
        • Q(b);P_SPINQ(b)::S(F)
      • Refutation
        • K(d);S_FLIGHT,XS(F)
    • Try
      • Q(B);P_PINQ(b),XP(a)
      • Threat
        • QAR1(B),XQ(b)
      • Vars
        • K(d);N_SPINQ(b),OGATEB,S_FLIGHT,XS(F)::QAB1(B)
        • Q(b);::S(F)
      • Refutation
        • Q(b);CHECK,N_SPINQ(b),XQ(B)
  • Actual
    • Q(B);
    • Threat
      • QAR1(B),XQ(b)
    • Vars
      • K(d);OGATEB,S_FLIGHT,XS(F)::QAB1(B)
      • Q(b);OGATE,XB(D)::QAR1(B)
      • Q(b);XQ(B)::S(F),XQ(b)
      • Q(b);N_GUARD,P_PINP(C),SBLOCK,XS(F)::QAR(B)
      • Q(b);OGATE::QAR1(B)
      • Q(b);OGATE::QAR1(B),XQ(b)
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