MESON Chess Problem Database

Problem Display
PID: 208845 (Qnqb4/2PkP3/5PN1/3B4/8/2n5/5B2/2K5 w - - 0 1)

Barrier, ?

Detroit Free Press, 1876

Qnqb4/2PkP3/5PN1/3B4/8/2n5/5B2/2K5

#2

8 + 5

6490 yacpdb 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Qa6
      • 2.cxd8Q#
      • 2.exd8Q#
    • 1...Qb7
      • 2.cxd8Q#
      • 2.exd8Q#
    • 1...Sa6
      • 2.Qc6#
    • 1...Sc6
      • 2.Qxc6#
  • Tries
    • 1.Se5+?
      • 1...Kxc7
        • 2.e8S#
      • 1...Ke8
        • 2.Bf7#
      • 1...Kd6!
    • 1.cxd8R+?
      • 1...Kc7
        • 2.Qa5#
      • 1...Qxd8!
    • 1.exd8R+?
      • 1...Kxc7
        • 2.Qa5#
      • 1...Qxd8!
  • Keys
    • 1.cxb8S+!
      • 1...Kd6
        • 2.e8S#
      • 1...Kc7
        • 2.e8S#
      • 1...Ke8
        • 2.f7#
      • 1...Qxb8
        • 2.Qc6#

FEATURES

  • Static
    • TYPE = CHECKING_KEY
    • CHANGED MATES = 0
    • ADDED MATES = 4
    • REMOVED MATES = 2
  • Sets
    • S(c);N_GUARD::QAB1(H)
    • S(c);N_GUARD::QAB1(H),XS(c)
  • Tries
    • Try
      • S(E);CHECK
      • Vars
        • K(b);P-FLIGHT,XP(F)::P=S
        • K(b);S_FLIGHT::B(C)
      • Refutation
        • K(b);P-FLIGHT
    • Try
      • P(F);CHECK,XB(e)
      • Vars
        • K(b);P-FLIGHT::QAB(H)
      • Refutation
        • Q(d);XR(F)
    • Try
      • P(G);CHECK,XB(e)
      • Vars
        • K(b);P-FLIGHT,XP(F)::QAB(H)
      • Refutation
        • Q(d);XR(G)
  • Actual
    • P(F);CHECK,XS(c)
    • Vars
      • K(b);P-FLIGHT::P=S
      • K(b);S_FLIGHT::P(D)
      • Q(d);XS(F)::QAB1(H)
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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).