MESON Chess Problem Database

Problem Display
PID: 456 (6b1/8/4n3/4k3/1K5R/5Q1B/8/4B3 w - - 0 1)

Ager, GC

The Observer, 1956

6b1/8/4n3/4k3/1K5R/5Q1B/8/4B3

#2

5 + 3

6490 yacpdb 2009

SOLUTION

  • SOUND
  • Sets
    • 1...Sd4
      • 2.Bg3#
    • 1...Sc5
      • 2.Bg3#
    • 1...Sg5
      • 2.Bg3#
    • 1...Sc7
      • 2.Bg3#
    • 1...Sg7
      • 2.Bg3#
    • 1...Sd8
      • 2.Bg3#
    • 1...Sf8
      • 2.Bg3#
  • Tries
    • 1.Qf4+?
      • 1...Kd5
        • 2.Bg2#
      • 1...Sxf4!
  • Keys
    • 1.Rd4!
      • threat
        • 2.Rd5#
      • 1...Kxd4
        • 2.Bc3#
      • 1...Sxd4
        • 2.Bg3#
      • 1...Sf4
        • 2.Qxf4#
      • 1...Sc5
        • 2.Qf4#
      • 1...Sg5
        • 2.Qf4#
      • 1...Sc7
        • 2.Qf4#
      • 1...Sg7
        • 2.Qf4#
      • 1...Sd8
        • 2.Qf4#
      • 1...Sf8
        • 2.Qf4#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 6
    • ADDED MATES = 2
    • REMOVED MATES = 0
  • Sets
    • S(b);N_GUARD::B(A)
  • Tries
    • Try
      • Q(B);CHECK
      • Vars
        • K(a);P-FLIGHT::B(C)
      • Refutation
        • S(b);XQ(B)
  • Actual
    • R(E);
    • Threat
      • R1(E)
    • Vars
      • K(a);OGATEB,S_FLIGHT,XR(E)::B(A)
      • S(b);N_GUARD,SBLOCK,XR(E)::B(A)
      • S(b);N_GUARD::QAB1(B),XS(b)
      • S(b);N_GUARD::QAB1(B)
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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).