MESON Chess Problem Database

Problem Display
PID: 58714 (6rk/6RB/7P/8/K7/8/8/7Q w - - 0 1)

Touw Hian Bwee

Chess Life, 1960

6rk/6RB/7P/8/K7/8/8/7Q

#2

5 + 2

5454 Near Snap 2007
3713 Snap 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Ra8+
      • 2.Qxa8#
  • Tries
    • 1.Qa8?
      • threat
        • 2.Qxg8#
      • 1...Rb8
        • 2.Qxb8#
      • 1...Rc8
        • 2.Qxc8#
      • 1...Rd8
        • 2.Qxd8#
      • 1...Re8
        • 2.Qxe8#
      • 1...Rf8
        • 2.Qxf8#
      • 1...Rxa8+!
  • Keys
    • 1.Qa1!
      • 1...Ra8+
        • 2.Ra7#
      • 1...Rxg7
        • 2.Qxg7#
      • 1...Rb8
        • 2.Rb7#
      • 1...Rc8
        • 2.Rc7#
      • 1...Rd8
        • 2.Rd7#
      • 1...Re8
        • 2.Re7#
      • 1...Rf8
        • 2.Rf7#

Anticipated by 6295(1928), 24909(1928), 205822(1932), 263960(1939), 16408(1940), 51226(1955)

This anticipates 52578(0000), 210889(1985), 240458(1992)

FEATURES

  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 1
    • ADDED MATES = 6
    • REMOVED MATES = 0
  • Sets
    • R(a);CHECK,OGATEB::QAB1(A),XR(a)
  • Tries
    • Try
      • Q(A);P_PINR(a)
      • Threat
        • QAR1(A),XR(a)
      • Vars
        • R(a);OGATEB::QAR(A),XR(a)
        • R(a);OGATEB::QAR2(A),XR(a)
      • Refutation
        • R(a);CHECK,N_SPINR(a),XQ(A)
  • Actual
    • Q(A);
    • Vars
      • R(a);CHECK,N_GUARD::QAB(A)+R(D)
      • R(a);OGATE,P_SPINR(a),XR(D)::QAB1(A),XR(a)
      • R(a);N_GUARD::QAB(A)+R(D)
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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).