MESON Chess Problem Database

Problem Display
PID: 192762 (1qn1n3/p1N4r/2Pk3r/Bp5p/5P2/5N2/6B1/K1R1R3 w - - 0 1)

Byas, Walter

The Observer, 1939

(First published on Sun Jul 16 1939)

1qn1n3/p1N4r/2Pk3r/Bp5p/5P2/5N2/6B1/K1R1R3

#2

9 + 9

15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Re6
      • 2.Rxe6#
    • 1...Re7
      • 2.Red1#
    • 1...Sf6
      • 2.Re6#
  • Tries
    • 1.Sxb5+?
      • 1...Kd5
        • 2.Sg1#
        • 2.Sd2#
        • 2.Sh2#
        • 2.Sfd4#
        • 2.Sh4#
        • 2.Sg5#
      • 1...Qxb5!
  • Keys
    • 1.Sg5!
      • threat
        • 2.Sxe8#
      • 1...Qxc7
        • 2.Bb4#
      • 1...Rxc7
        • 2.Bb4#
      • 1...Sxc7
        • 2.Bb4#
      • 1...Re6
        • 2.Rxe6#
      • 1...Sb6
        • 2.Sxb5#
      • 1...Se7
        • 2.Se4#
      • 1...Re7
        • 2.Red1#
      • 1...Rh8
        • 2.Sf7#
      • 1...Sf6
        • 2.Re6#
      • 1...Sg7
        • 2.Sf7#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 7
    • REMOVED MATES = 0
  • Sets
    • R(d);N_GUARD::R1(C),XR(d)
    • R(f);SBLOCK::R(C)
    • S(i);S_CUTR(d)::R1(C)
  • Tries
    • Try
      • S(I);CHECK,XP(a)
      • Refutation
        • Q(g);XS(I)
  • Actual
    • S(E);
    • Threat
      • S(I),XS(i)
    • Vars
      • Q(g);SBLOCK,XS(I)::B(G)
      • R(f);SBLOCK,XS(I)::B(G)
      • S(i);SBLOCK,XS(I)::B(G)
      • R(d);N_GUARD::R1(C),XR(d)
      • S(h);S_CUTQ(g)::S(I),XP(a)
      • S(h);SBLOCK::S(E)
      • R(f);SBLOCK::R(C)
      • R(f);N_GUARD::S(E)
      • S(i);S_CUTR(d)::R1(C)
      • S(i);S_CUTR(f)::S(E)
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