MESON Chess Problem Database

Problem Display
PID: 478 (6bb/4p3/2K4R/2Qn1kpn/1pN3p1/3Pp1P1/2r1N3/1B6 w - - 0 1)

Swords, WJ

The Observer, 1956

6bb/4p3/2K4R/2Qn1kpn/1pN3p1/3Pp1P1/2r1N3/1B6

#2

8 + 11

SOLUTION

  • SOUND
  • Sets
    • 1...Bd4
      • 2.Sxd4#
    • 1...Sf6
      • 2.Sd4#
    • 1...Sg7
      • 2.Sd4#
    • 1...e5
      • 2.Sd6#
  • Tries
    • 1.Sd6+?
      • 1...Ke5
        • 2.d4#
      • 1...exd6!
    • 1.Qxd5+?
      • 1...Be5
        • 2.Sd4#
        • 2.Qe4#
        • 2.Qxe5#
      • 1...e5
        • 2.Sd4#
        • 2.Qe4#
      • 1...Bxd5+!
  • Keys
    • 1.Qd4!
      • threat
        • 2.Qe4#
      • 1...Rxc4+
        • 2.dxc4#
      • 1...Bxd4
        • 2.Sxd4#
      • 1...Sxg3
        • 2.Sxg3#
      • 1...Sdf6
        • 2.Qe5#
      • 1...Shf6
        • 2.Qe5#
      • 1...Sc3
        • 2.Sxe3#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 4
    • REMOVED MATES = 2
  • Sets
    • B(k);N_GUARD::S(B),XB(k)
    • S(h);S_CUTB(k)::S(B)
    • P(i);N_GUARD,N_SPINS(e),SBLOCK::S(E)
  • Tries
    • Try
      • S(E);CHECK,P_SPINQ(F)
      • Vars
        • K(f);P-FLIGHT::P(C)
      • Refutation
        • P(i);XS(E)
    • Try
      • Q(F);CHECK,P_SPINS(E),XS(e)
      • Refutation
        • B(j);CHECK,XQ(F)
  • Actual
    • Q(F);N_PINS(e),P_SPINS(E)
    • Threat
      • QAB1(F)
    • Vars
      • R(a);CHECK,OGATE,XS(E)::B(A)+P(C),XR(a)
      • B(k);XQ(F)::S(B),XB(k)
      • S(h);XP(D)::S(B),XS(h)
      • S(e);S_CUTB(k)::QAR1(F)
      • S(h);S_CUTB(k)::QAR1(F)
      • S(e);N_PINS(E)::S(E),XP(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).