MESON Chess Problem Database

Problem Display
PID: 190294 (1b3r2/1K2N3/5n2/3P3B/5knB/4pP1b/6R1/3Q4 w - - 0 1)

Sumner, Christopher Richard Benson

The Observer, 1938

(First published on Sun Mar 27 1938)

1b3r2/1K2N3/5n2/3P3B/5knB/4pP1b/6R1/3Q4

#2

8 + 7

15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Ke5
      • 2.Bg3#
    • 1...Se5
      • 2.Bg5#
  • Tries
    • 1.Qa4+?
      • 1...Ke5
        • 2.Bg3#
      • 1...Se4
        • 2.Qxe4#
      • 1...Kxf3!
    • 1.Qd4+?
      • 1...Se4
        • 2.Qxe4#
      • 1...Kxf3!
  • Keys
    • 1.Qd3!
      • threat
        • 2.Qf5#
      • 1...Kxf3
        • 2.Rf2#
      • 1...Ke5
        • 2.Bg3#
      • 1...Sxd5
        • 2.Qe4#
      • 1...Sxh5
        • 2.Qe4#
      • 1...Sf2
        • 2.Sg6#
      • 1...Sh2
        • 2.Sg6#
      • 1...Se5
        • 2.Bg5#
      • 1...Sh6
        • 2.Sg6#
      • 1...Se4
        • 2.Qxe4#
      • 1...Sd7
        • 2.Qe4#
      • 1...Sh7
        • 2.Qe4#
      • 1...Se8
        • 2.Qe4#
      • 1...Sg8
        • 2.Qe4#
      • 1...e2
        • 2.Sg6#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 12
    • REMOVED MATES = 0
  • Sets
    • K(c);S_FLIGHT::B(D)
    • S(d);SBLOCK::B(D)
  • Tries
    • Try
      • Q(A);CHECK
      • Vars
        • K(c);S_FLIGHT::B(D)
        • S(e);N_GUARD,P_SPINS(e)::QAR1(A),XS(e)
      • Refutation
        • K(c);P-FLIGHT,P_SPINS(d),XP(C)
    • Try
      • Q(A);CHECK
      • Vars
        • S(e);N_GUARD,P_SPINS(e)::QAR1(A),XS(e)
      • Refutation
        • K(c);P-FLIGHT,P_SPINS(d),XP(C)
  • Actual
    • Q(A);
    • Threat
      • QAR1(A)
    • Vars
      • K(c);OGATEB,P-FLIGHT,P_SPINP(a),P_SPINS(d),XP(C)::R1(B)
      • K(c);S_FLIGHT::B(D)
      • S(e);N_GUARD,XP(E)::QAR1(A)
      • S(e);N_GUARD,XB(F)::QAR1(A)
      • S(d);::S(H)
      • S(d);SBLOCK::B(D)
      • S(e);N_GUARD::QAR1(A),XS(e)
      • S(e);N_GUARD::QAR1(A)
      • P(a);::S(H)
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