MESON Chess Problem Database

Problem Display
PID: 153661 (4K3/5p2/1Q4Rp/7k/4p2p/6bN/8/8 w - - 0 1)

Harley, Brian

The Observer, 1945

(First published on Sun May 6 1945)

4K3/5p2/1Q4Rp/7k/4p2p/6bN/8/8

#2

4 + 6

15290 Harley Scrapbook 2015
15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Be1
      • 2.Sf4#
    • 1...Bf2
      • 2.Sf4#
    • 1...Bf4
      • 2.Sxf4#
  • Tries
    • 1.Qe3?
      • threat
        • 2.Qxh6#
      • 1...fxg6
        • 2.Qe2#
      • 1...Bf4
        • 2.Sxf4#
      • 1...Kxg6!
    • 1.Qa5+?
      • 1...Be5
        • 2.Sf4#
      • 1...f5
        • 2.Qxf5#
      • 1...Kxg6!
    • 1.Qc5+?
      • 1...Be5
        • 2.Sf4#
      • 1...f5
        • 2.Qxf5#
      • 1...Kxg6!
    • 1.Qb5+?
      • 1...Be5
        • 2.Sf4#
      • 1...f5
        • 2.Qxf5#
      • 1...Kxg6!
    • 1.Qf6?
      • threat
        • 2.Qf5#
      • 1...Bf4
        • 2.Sxf4#
      • 1...fxg6!
  • Keys
    • 1.Qf2!
      • threat
        • 2.Qf5#
      • 1...Kxg6
        • 2.Qxf7#
      • 1...Bxf2
        • 2.Sf4#
      • 1...fxg6
        • 2.Qe2#
      • 1...Bf4
        • 2.Sxf4#
      • 1...f5
        • 2.Qxf5#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 1
  • Sets
    • B(a);N_GUARD::S(A)
    • B(a);N_GUARD::S(A),XB(a)
  • Tries
    • Try
      • Q(B);
      • Threat
        • QAR1(B),XP(e)
      • Vars
        • P(f);SBLOCK,XR(C)::QAB(B)
        • B(a);N_GUARD::S(A),XB(a)
      • Refutation
        • K(d);S_FLIGHT,XR(C)
    • Try
      • Q(B);CHECK
      • Vars
        • B(a);P_SPINB(a)::S(A)
        • P(f);P_SPINP(f)::QAR2(B),XP(f)
      • Refutation
        • K(d);S_FLIGHT,XR(C)
    • Try
      • Q(B);CHECK
      • Vars
        • B(a);P_SPINB(a)::S(A)
        • P(f);P_SPINP(f)::QAR2(B),XP(f)
      • Refutation
        • K(d);S_FLIGHT,XR(C)
    • Try
      • Q(B);CHECK
      • Vars
        • B(a);P_SPINB(a)::S(A)
        • P(f);P_SPINP(f)::QAR2(B),XP(f)
      • Refutation
        • K(d);S_FLIGHT,XR(C)
    • Try
      • Q(B);
      • Threat
        • QAR2(B)
      • Vars
        • B(a);N_GUARD::S(A),XB(a)
      • Refutation
        • P(f);XR(C)
  • Actual
    • Q(B);
    • Threat
      • QAR2(B)
    • Vars
      • K(d);OGATEB,S_FLIGHT,XR(C)::QAB1(B),XP(f)
      • B(a);N_GUARD,XQ(B)::S(A)
      • P(f);SBLOCK,XR(C)::QAB(B)
      • B(a);N_GUARD::S(A),XB(a)
      • P(f);::QAR2(B),XP(f)
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