MESON Chess Problem Database

Problem Display
PID: 210349 (Q1B2B2/brp3PK/N2PP3/n2kN2R/R7/2P5/2n5/8 w - - 0 1)

Franken, Maurits

The Observer, 1920

(First published on Sun Oct 31 1920)

Q1B2B2/brp3PK/N2PP3/n2kN2R/R7/2P5/2n5/8

#2

12 + 6

15239 Valois Notebooks 2020
5454 Near Snap 2022

SOLUTION

  • SOUND
  • Sets
    • 1...Bc5
      • 2.Sxc7#
    • 1...c5
      • 2.Sc7#
    • 1...c6
      • 2.Sd3#
      • 2.Sf3#
      • 2.Sg4#
      • 2.Sg6#
      • 2.Sf7#
  • Tries
    • 1.Sc4+?
      • 1...Kc6
        • 2.Bd7#
      • 1...Ke4!
    • 1.Sd7+?
      • 1...Kxe6
        • 2.g8Q#
        • 2.g8B#
      • 1...Kc6!
    • 1.Qxb7+?
      • 1...Sc6
        • 2.Sd3#
        • 2.Sf3#
        • 2.Sg4#
        • 2.Sxc6#
        • 2.Sg6#
        • 2.Sf7#
        • 2.Qxc6#
        • 2.Qb3#
      • 1...c6
        • 2.Sd3#
        • 2.Sf3#
        • 2.Sg4#
        • 2.Sxc6#
        • 2.Sg6#
        • 2.Sf7#
      • 1...Sxb7!
  • Keys
    • 1.g8S!
      • threat
        • 2.Sf6#
      • 1...cxd6+
        • 2.Se7#
      • 1...c5+
        • 2.Sc7#
      • 1...c6+
        • 2.Sf7#

This anticipates 239596(1968)

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 2
    • REMOVED MATES = 1
  • Sets
    • B(d);SBLOCK::S(E),XP(f)
    • P(f);P_PINP(H),SBLOCK::S(E)
  • Tries
    • Try
      • S(C);CHECK
      • Vars
        • K(c);S_FLIGHT::B(K)
      • Refutation
        • K(c);S_FLIGHT
    • Try
      • S(C);CHECK
      • Vars
        • K(c);N_SPINR(e),S_FLIGHT,XP(G)::P=Q
      • Refutation
        • K(c);S_FLIGHT
    • Try
      • Q(J);CHECK,XR(e)
      • Refutation
        • S(b);XQ(J)
  • Actual
    • P(H);
    • Threat
      • S(H)
    • Vars
      • P(f);CHECK,SBLOCK,XP(F)::S(H)
      • P(f);CHECK,SBLOCK::S(E)
      • P(f);CHECK,N_SPINR(e),SBLOCK::R(D)+S(C)
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