Problem Display
PID: 143573 (8/1K6/8/2pk4/6Q1/8/2PnP2B/8 w - - 0 1)

Challenger, Alfred Clement

British Chess Magazine, 1895

8/1K6/8/2pk4/6Q1/8/2PnP2B/8

#2

5 + 3


15 British Chess Magazine 1910
5454 Near Snap 2012
3713 Snap 2012

SOLUTION


  • SOUND
  • Sets
    • 1...Sb1
      • 2.c4#
    • 1...Sf1
      • 2.c4#
    • 1...Sb3
      • 2.c4#
    • 1...Sf3
      • 2.c4#
  • Tries
    • 1.Qf5+?
      • 1...Kd4
        • 2.Qd3#
      • 1...Kc4!
    • 1.Qd7+?
      • 1...Ke4
        • 2.Qd3#
      • 1...Kc4!
    • 1.e3?
      • 1...Se4
        • 2.Qg8#
      • 1...c4
        • 2.Qf5#
      • 1...Sb1
        • 2.c4#
      • 1...Sf1
        • 2.c4#
      • 1...Sb3
        • 2.c4#
      • 1...Sf3
        • 2.c4#
      • 1...Sc4!
  • Keys
    • 1.c3!
      • 1...Se4
        • 2.Qg8#
      • 1...c4
        • 2.Qf5#
      • 1...Sb1
        • 2.c4#
      • 1...Sf1
        • 2.c4#
      • 1...Sb3
        • 2.c4#
      • 1...Sf3
        • 2.c4#
      • 1...Sc4
        • 2.e4#

Anticipated by 4877(1892)

This anticipates 178120(1900), 49145(1906), 16389(1940), 96887(1945), 24689(1987)

FEATURES


  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 0
  • Sets
    • S(a);N_GUARD::P(A)
  • Tries
    • Try
      • Q(D);CHECK
      • Vars
        • K(c);P-FLIGHT::QAR1(D)
      • Refutation
        • K(c);S_FLIGHT
    • Try
      • Q(D);CHECK
      • Vars
        • K(c);OGATE,S_FLIGHT::QAB1(D)
      • Refutation
        • K(c);S_FLIGHT
    • Try
      • P(B);
      • Vars
        • S(a);SBLOCK::QAB(D)
        • P(b);SBLOCK::QAR2(D)
        • S(a);N_GUARD::P(A)
      • Refutation
        • S(a);
  • Actual
    • P(A);
    • Vars
      • S(a);SBLOCK::QAB(D)
      • P(b);SBLOCK::QAR2(D)
      • S(a);N_GUARD::P(A)
      • S(a);N_GUARD,SBLOCK::P(B)


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).