Problem Display
PID: 21312 (b3Qn2/3p4/4qB1K/8/6R1/4k2N/R3P3/8 w - - 0 1)

White, Alain Campbell

1st Prize, Good Companions, 1918

b3Qn2/3p4/4qB1K/8/6R1/4k2N/R3P3/8

#2

7 + 5


3147 Chess Problems: Introduction to an Art 1963
3713 Snap 2014

SOLUTION


  • SOUND
  • Sets
    • 1...Qe4
      • 2.Rg3#
    • 1...Qe5
      • 2.Bg5#
    • 1...Qe7
      • 2.Bd4#
      • 2.Bg5#
    • 1...Qxe8
      • 2.Bd4#
      • 2.Bg5#
    • 1...Sg6
      • 2.Bd4#
  • Tries
    • 1.Qxe6+?
      • 1...Be4
        • 2.Rg3#
        • 2.Rxe4#
        • 2.Qxe4#
        • 2.Qb6#
      • 1...dxe6
        • 2.Bd4#
        • 2.Bg5#
      • 1...Sxe6!
  • Keys
    • 1.Qe7!
      • threat
        • 2.Qc5#
      • 1...Qxe7
        • 2.Bd4#
      • 1...Qe4
        • 2.Rg3#
      • 1...Qe5
        • 2.Bg5#
      • 1...d5
        • 2.Qa3#
      • 1...d6
        • 2.Qa7#

This anticipates 152056(1951)

FEATURES


  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 1
  • Sets
    • Q(b);N_PINB(E),S_CUTB(d)::R(D)
    • Q(b);N_PINB(E)::B(E)
    • S(e);N_PINB(E)::B(E)
  • Tries
    • Try
      • Q(G);CHECK,N_SPINB(E),XQ(b)
      • Refutation
        • S(e);XQ(G)
  • Actual
    • Q(G);
    • Threat
      • QAB(G)
    • Vars
      • Q(b);N_PINB(E),N_SPINQ(b),XQ(G)::B(E)
      • Q(b);N_PINB(E),S_CUTB(d)::R(D)
      • Q(b);N_PINB(E)::B(E)
      • P(c);::QAR(G)
      • P(c);OGATE::QAB(G)


Developed and maintained by Brian Stephenson.
Implemented with HTML5, MySQL, Perl (with, inter alia, CGI::Simple, HTML::Template & XML::LibXML) & CSS/Javascript (jQuery, Bootstrap & DataTables).