MESON Chess Problem Database

Problem Display
PID: 153375 (1BKn4/3N4/k1p5/pp6/4Q3/8/5p2/5B2 w - - 0 1)

Harley, Brian

The Observer, 1940

(First published on Sun Aug 18 1940)

1BKn4/3N4/k1p5/pp6/4Q3/8/5p2/5B2

#2

5 + 6

15290 Harley Scrapbook 2014
15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Se6
      • 2.Qxc6#
    • 1...Sb7
      • 2.Qxc6#
    • 1...Sf7
      • 2.Qxc6#
    • 1...a4
      • 2.Qxa4#
    • 1...c5
      • 2.Qa8#
  • Tries
    • 1.Kc7?
      • threat
        • 2.Sc5#
      • 1...a4
        • 2.Qxa4#
      • 1...Sb7
        • 2.Qxc6#
      • 1...c5
        • 2.Sxc5#
        • 2.Qa8#
      • 1...Se6+!
    • 1.Bxb5+?
      • 1...cxb5
        • 2.Qa8#
      • 1...Kxb5!
    • 1.Qh1?
      • 1...Se6
        • 2.Qxc6#
      • 1...Sb7
        • 2.Qxc6#
      • 1...Sf7
        • 2.Qxc6#
      • 1...c5
        • 2.Qa8#
      • 1...a4!
    • 1.Qc2?
      • 1...a4
        • 2.Qxa4#
      • 1...Se6
        • 2.Qxc6#
      • 1...Sb7
        • 2.Qxc6#
      • 1...Sf7
        • 2.Qxc6#
      • 1...c5!
    • 1.Qg2?
      • 1...Se6
        • 2.Qxc6#
      • 1...Sb7
        • 2.Qxc6#
      • 1...Sf7
        • 2.Qxc6#
      • 1...c5
        • 2.Qa8#
      • 1...a4!
    • 1.Qf3?
      • 1...Se6
        • 2.Qxc6#
      • 1...Sb7
        • 2.Qxc6#
      • 1...Sf7
        • 2.Qxc6#
      • 1...c5
        • 2.Qa8#
      • 1...a4!
  • Keys
    • 1.Qc4!
      • 1...bxc4
        • 2.Bxc4#
      • 1...a4
        • 2.Qxa4#
      • 1...Se6
        • 2.Qxc6#
      • 1...Sb7
        • 2.Qxc6#
      • 1...Sf7
        • 2.Qxc6#
      • 1...c5
        • 2.Qxb5#

FEATURES

  • Static
    • TYPE = MUTATE
    • CHANGED MATES = 1
    • ADDED MATES = 1
    • REMOVED MATES = 0
  • Sets
    • S(f);N_GUARD::QAR2(B),XP(e)
    • P(b);OGATEB::QAR2(B),XP(b)
    • P(e);OGATE::QAR2(B)
  • Tries
    • Try
      • K(E);P-FLIGHT
      • Threat
        • S(C)
      • Vars
        • P(b);OGATEB::QAR2(B),XP(b)
        • S(f);N_GUARD::QAR2(B),XP(e)
      • Refutation
        • S(f);CHECK
    • Try
      • B(A);CHECK,XP(c)
      • Vars
        • P(e);OGATE,SBLOCK,XB(A)::QAR2(B)
      • Refutation
        • K(d);S_FLIGHT,XB(A)
    • Try
      • Q(B);
      • Vars
        • S(f);N_GUARD::QAR2(B),XP(e)
        • P(e);OGATE::QAR2(B)
      • Refutation
        • P(b);
    • Try
      • Q(B);
      • Vars
        • P(b);OGATEB::QAR2(B),XP(b)
        • S(f);N_GUARD::QAR2(B),XP(e)
      • Refutation
        • P(e);
    • Try
      • Q(B);
      • Vars
        • S(f);N_GUARD::QAR2(B),XP(e)
        • P(e);OGATE::QAR2(B)
      • Refutation
        • P(b);
    • Try
      • Q(B);
      • Vars
        • S(f);N_GUARD::QAR2(B),XP(e)
        • P(e);OGATE::QAR2(B)
      • Refutation
        • P(b);
  • Actual
    • Q(B);
    • Vars
      • P(c);OGATE,XQ(B)::B(A),XP(c)
      • P(b);OGATEB::QAR2(B),XP(b)
      • S(f);N_GUARD::QAR2(B),XP(e)
      • P(e);N_GUARD::QAB1(B),XP(c)
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).