MESON Chess Problem Database

Problem Display
PID: 270716 (Q2BR3/3p1pbB/1K2b2r/2PPkN2/4p1p1/4P2p/8/8 w - - 0 1)

Lertoria, Ernest

The Observer, 1959

(First published on Sun Jul 5 1959)

Q2BR3/3p1pbB/1K2b2r/2PPkN2/4p1p1/4P2p/8/8

#2

9 + 9

17397 Ling Notebooks 2023

SOLUTION

  • SOUND
  • Tries
    • 1.Sxh6?
      • threat
        • 2.Sxg4#
        • 2.Sxf7#
      • 1...g3
        • 2.Sg4#
        • 2.Sxf7#
      • 1...f5
        • 2.Sf7#
      • 1...f6
        • 2.Sxg4#
        • 2.Sf7#
      • 1...Bxh6!
    • 1.Bc7+?
      • 1...Kf6
        • 2.Qd8#
      • 1...d6!
    • 1.Qb8+?
      • 1...d6
        • 2.Qxd6#
      • 1...Kxd5!
  • Keys
    • 1.Se7!
      • threat
        • 2.Qa1#
      • 1...Bxd5+
        • 2.Sc6#
      • 1...Bf5+
        • 2.Sg6#
      • 1...Kf6
        • 2.Sc6#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 0
  • Sets
  • Tries
    • Try
      • S(D);XR(f)
      • Threat
        • DUALS(2)
      • Vars
        • P(h);::S(D)
      • Refutation
        • B(i);XS(D)
    • Try
      • B(H);CHECK
      • Vars
        • K(d);N_GUARD,N_SPINB(e),S_CUTP(g),S_FLIGHT::QAB(G)
      • Refutation
        • P(g);P_SPINP(g)
    • Try
      • Q(G);CHECK
      • Vars
        • P(g);P_SPINP(g)::QAB1(G),XP(g)
      • Refutation
        • K(d);N_SPINB(e),P-FLIGHT,XP(C)
  • Actual
    • S(D);N_PINB(e)
    • Threat
      • QAB(G)
    • Vars
      • B(e);CHECK,SBLOCK,XP(C)::R(I)+S(D),DCHECK
      • B(e);CHECK,SBLOCK::R(I)+S(D),DCHECK
      • K(d);N_GUARD,S_CUTP(g),S_FLIGHT::B(H)+S(D)
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