MESON Chess Problem Database

Problem Display
PID: 185183 (n5Bb/2P1R3/1r1pN3/1p1kr2R/1P4P1/3p4/b2K4/2Q5 w - - 0 1)

Sumner, Christopher Richard Benson

The Observer, 1930

(First published on Sun Aug 24 1930)

n5Bb/2P1R3/1r1pN3/1p1kr2R/1P4P1/3p4/b2K4/2Q5

#2

9 + 9

15239 Valois Notebooks 2018

SOLUTION

  • SOUND
  • Sets
    • 1...Ke4
      • 2.Qh1#
    • 1...Bc4
      • 2.Qh1#
  • Tries
    • 1.Sc5+?
      • 1...Kd4
        • 2.Qb2#
        • 2.Qa1#
        • 2.Qc3#
      • 1...Kc6!
    • 1.Sg5+?
      • 1...Kd4
        • 2.Qb2#
        • 2.Qa1#
        • 2.Qc3#
      • 1...Re6!
    • 1.Qc6+?
      • 1...Kxc6
        • 2.Sd8#
      • 1...Rxc6!
  • Keys
    • 1.Kc3!
      • threat
        • 2.Qh1#
      • 1...Rf5+
        • 2.Sd4#
      • 1...Rg5+
        • 2.Sd4#
      • 1...Rxh5+
        • 2.Sd4#
      • 1...Rc6+
        • 2.Sc5#
      • 1...Ke4
        • 2.Sg5#
      • 1...Kc6
        • 2.Sd8#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 5
    • REMOVED MATES = 1
  • Sets
    • K(d);N_SPINR(e),S_FLIGHT::QAB(A)
    • B(a);SBLOCK::QAB(A)
  • Tries
    • Try
      • S(F);CHECK
      • Refutation
        • K(d);N_SPINR(e),S_FLIGHT
    • Try
      • S(F);CHECK,N_PINR(e)
      • Refutation
        • R(e);P_SPINR(e)
    • Try
      • Q(A);CHECK
      • Vars
        • K(d);N_SPINR(e),S_FLIGHT,XQ(A)::S(F)
      • Refutation
        • R(f);XQ(A)
  • Actual
    • K(B);S_FLIGHT
    • Threat
      • QAB(A)
    • Vars
      • R(e);CHECK::B(I)+S(F)
      • R(e);CHECK,N_SPINR(e),XR(E)::B(I)+S(F)
      • R(f);CHECK,SBLOCK::B(I)+S(F)
      • K(d);N_SPINR(e),S_FLIGHT::S(F)
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