MESON Chess Problem Database

Problem Display
PID: 186207 (8/2KP1B2/3R2P1/QNp2k1r/n6p/3P1PbN/4rpR1/B7 w - - 0 1)

Penrose, Lionel Sharples

The Observer, 1932

(First published on Sun Oct 2 1932)

8/2KP1B2/3R2P1/QNp2k1r/n6p/3P1PbN/4rpR1/B7

#2

12 + 8

15239 Valois Notebooks 2018

SOLUTION

  • SOUND
  • Sets
    • 1...Re4
      • 2.dxe4#
    • 1...Bxd6+
      • 2.Sxd6#
    • 1...c4
      • 2.Sd4#
  • Tries
    • 1.Bh8?
      • threat
        • 2.Sd4#
      • 1...Bxd6+
        • 2.Sxd6#
      • 1...Re4
        • 2.dxe4#
      • 1...Re5
        • 2.Rf6#
      • 1...Be5
        • 2.Be6#
      • 1...Rxh8!
  • Keys
    • 1.Bg7!
      • threat
        • 2.Sd4#
      • 1...Bxd6+
        • 2.Sxd6#
      • 1...Re4
        • 2.dxe4#
      • 1...Re5
        • 2.Rf6#
      • 1...Be5
        • 2.Be6#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 2
    • REMOVED MATES = 1
  • Sets
    • R(a);OGATE::P(C),XR(a)
    • B(c);CHECK,XR(H)::S(G),XB(c)
    • P(f);::QAR(F)+S(G),DCHECK
  • Tries
    • Try
      • B(A);
      • Threat
        • S(G)
      • Vars
        • B(c);CHECK,XR(H)::S(G),XB(c)
        • R(a);OGATE::P(C),XR(a)
        • R(a);N_PINR(H),SBLOCK::R1(H)
        • B(c);S_CUTR(a)::B(L)
      • Refutation
        • R(h);XB(A)
  • Actual
    • B(A);
    • Threat
      • S(G)
    • Vars
      • B(c);CHECK,XR(H)::S(G),XB(c)
      • R(a);OGATE::P(C),XR(a)
      • R(a);N_PINR(H),SBLOCK::R1(H)
      • B(c);S_CUTR(a)::B(L)
HTML5 logo

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).