MESON Chess Problem Database

Problem Display
PID: 184162 (b7/1n6/1R2B3/8/1p1k2N1/1PNp4/3p4/Q2K4 w - - 0 1)

Evans, TC

The Observer, 1927

(First published on Sun Sep 11 1927)

b7/1n6/1R2B3/8/1p1k2N1/1PNp4/3p4/Q2K4

#2

7 + 6

15239 Valois Notebooks 2018

SOLUTION

  • SOUND
  • Sets
    • 1...Kc5
      • 2.Sa4#
    • 1...Sc5
      • 2.Rxb4#
  • Tries
    • 1.Kxd2?
      • threat
        • 2.Qg1#
      • 1...Kc5
        • 2.Sa4#
        • 2.Qg1#
      • 1...bxc3+!
    • 1.Se2+?
      • 1...Kc5
        • 2.Qd4#
      • 1...Ke4!
    • 1.Sb5+?
      • 1...Kc5
        • 2.Qd4#
      • 1...Ke4!
    • 1.Qa5?
      • threat
        • 2.Qxb4#
        • 2.Qe5#
      • 1...Kxc3
        • 2.Qa1#
        • 2.Qe5#
      • 1...bxc3
        • 2.Rb4#
        • 2.Qb4#
        • 2.Qd5#
        • 2.Qe5#
      • 1...Sc5
        • 2.Qxb4#
      • 1...Sd6
        • 2.Qe5#
      • 1...Sxa5!
  • Keys
    • 1.Qa7!
      • 1...Kxc3
        • 2.Qa1#
      • 1...Kc5
        • 2.Ra6#
      • 1...bxc3
        • 2.Rb4#
      • 1...Sa5
        • 2.Rc6#
      • 1...Sc5
        • 2.Qg7#
      • 1...Sd6
        • 2.Rc6#
      • 1...Sd8
        • 2.Rc6#

FEATURES

  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 2
    • ADDED MATES = 5
    • REMOVED MATES = 0
  • Sets
    • K(d);S_FLIGHT::S(D)
    • S(e);SBLOCK::R(F),XP(c)
  • Tries
    • Try
      • K(B);P-FLIGHT,XP(a)
      • Threat
        • QAB(A)
      • Refutation
        • P(c);CHECK,P_SPINP(c),XS(D)
    • Try
      • S(D);CHECK
      • Vars
        • K(d);S_FLIGHT::QAB1(A)
      • Refutation
        • K(d);P-FLIGHT
    • Try
      • S(D);CHECK
      • Vars
        • K(d);S_FLIGHT::QAB1(A)
      • Refutation
        • K(d);P-FLIGHT
    • Try
      • Q(A);
      • Threat
        • DUALS(2)
      • Vars
        • S(e);::QAR2(A),XP(c)
        • S(e);::QAB1(A)
      • Refutation
        • S(e);XQ(A)
  • Actual
    • Q(A);
    • Vars
      • K(d);OGATEB,S_FLIGHT,XS(D)::QAB(A)
      • K(d);S_FLIGHT::QAB(A)+R(F)
      • P(c);SBLOCK,XS(D)::QAB(A)+R(F),DCHECK
      • S(e);N_GUARD::QAB(A)+R(F)
      • S(e);OGATE,SBLOCK::QAB(A)
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