MESON Chess Problem Database

Problem Display
PID: 202895 (8/2b2n2/3pb3/2Rr1p2/2BkNQ2/8/2K5/8 w - - 0 1)

Sprague, Gordon

The Observer, 1950

(First published on Sun Dec 24 1950)

8/2b2n2/3pb3/2Rr1p2/2BkNQ2/8/2K5/8

#2

5 + 7

15239 Valois Notebooks 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Rxc5
      • 2.Sd2#
      • 2.Sf2#
      • 2.Sc3#
      • 2.Sg3#
      • 2.Sg5#
      • 2.Sxd6#
      • 2.Sf6#
    • 1...dxc5
      • 2.Sd6#
  • Tries
    • 1.Rxd5+?
      • 1...Kxc4
        • 2.Sc3#
        • 2.Sf6#
      • 1...Bxd5!
  • Keys
    • 1.Bd3!
      • threat
        • 2.Rc4#
      • 1...Rxc5+
        • 2.Sc3#
      • 1...dxc5
        • 2.Sd6#
      • 1...Re5
        • 2.Qf2#
      • 1...Se5
        • 2.Qf2#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 0
  • Sets
    • P(d);SBLOCK,XR(E)::QAR(D)+S(C)
  • Tries
    • Try
      • R(E);CHECK,XR(b)
      • Refutation
        • B(e);XR(E)
  • Actual
    • B(B);
    • Threat
      • R1(E)
    • Vars
      • R(b);CHECK,SBLOCK,XR(E)::QAR(D)+S(C)
      • P(d);SBLOCK,XR(E)::QAR(D)+S(C)
      • R(b);::QAB(D)
      • S(g);SBLOCK::QAB(D)
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