MESON Chess Problem Database

Problem Display
PID: 460 (K7/8/3pp3/1R1pQ3/BNknn2R/B1p3p1/2Pprbb1/8 w - - 0 1)

Driver, John Edward

The Observer, 1956

K7/8/3pp3/1R1pQ3/BNknn2R/B1p3p1/2Pprbb1/8

#2

8 + 12

SOLUTION

  • SOUND
  • Sets
    • 1...Sb3
      • 2.cxb3#
    • 1...Sg5
      • 2.Qxe2#
    • 1...Sf6
      • 2.Qxe2#
  • Keys
    • 1.Sxd5!
      • threat
        • 2.Sb6#
      • 1...Sxc2
        • 2.Qxc3#
      • 1...Sxb5
        • 2.Bb3#
      • 1...exd5
        • 2.Qxd5#
      • 1...Sb3
        • 2.Qxc3#
      • 1...Sf3
        • 2.Qxc3#
      • 1...Sf5
        • 2.Qxc3#
      • 1...Sc6
        • 2.Qxc3#
      • 1...Sc5
        • 2.Rb4#
      • 1...Sg5
        • 2.Qxe2#
      • 1...Sf6
        • 2.Qxe2#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 7
    • REMOVED MATES = 0
  • Sets
    • S(h);OGATE,P_SPINS(i)::P(A),XS(h)
    • S(i);OGATE,P_SPINS(h)::QAB(G),XR(b)
  • Actual
    • S(D);XP(j)
    • Threat
      • S(D)
    • Vars
      • S(h);OGATE,P_SPINS(i),XP(A)::QAR1(G),XP(e)
      • S(h);N_GUARD,P_SPINS(i),SBLOCK,XR(F)::B(C)
      • P(l);OGATE,XS(D)::QAB1(G),XP(l)
      • S(h);OGATE,P_SPINS(i)::QAR1(G),XP(e)
      • S(i);P_PINS(D),P_SPINS(h),SBLOCK::R1(F)
      • S(i);OGATE,P_PINS(D),P_SPINS(h)::QAB(G),XR(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).