Problem Display
PID: 216193 (8/2pp1BQb/2N1p1p1/2Pk4/1K5b/6N1/4P3/8 w - - 0 1)

Collins, Francis Charles

A Collection of 107 Chess Problems, 1881

8/2pp1BQb/2N1p1p1/2Pk4/1K5b/6N1/4P3/8

#2

7 + 7


6490 yacpdb 2020

SOLUTION


  • SOUND
  • Sets
    • 1...Be7
      • 2.Sxe7#
    • 1...g5
      • 2.Se7#
    • 1...dxc6
      • 2.e4#
  • Tries
    • 1.Kb5?
      • threat
        • 2.Sb4#
        • 2.Qd4#
        • 2.Qe5#
        • 2.e4#
      • 1...Bxg3
        • 2.Qd4#
      • 1...Bf6
        • 2.e4#
      • 1...g5
        • 2.Sb4#
        • 2.Se7#
        • 2.Qd4#
        • 2.Qe5#
      • 1...d6
        • 2.Sb4#
        • 2.Qd4#
        • 2.e4#
      • 1...dxc6+!
    • 1.Qc3?
      • threat
        • 2.Qf3#
      • 1...dxc6
        • 2.e4#
      • 1...g5
        • 2.Se7#
      • 1...Kxc6!
  • Keys
    • 1.Qa1!
      • threat
        • 2.Qh1#
      • 1...Kxc6
        • 2.Qa8#
      • 1...dxc6
        • 2.e4#
      • 1...g5
        • 2.Se7#

FEATURES


  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 1
    • REMOVED MATES = 1
  • Sets
    • B(a);N_GUARD,P_PINP(D)::S(E),XB(a)
    • P(d);S_CUTB(a)::S(E)
    • P(f);SBLOCK,XS(E)::P(A)
  • Tries
    • Try
      • K(C);P-FLIGHT
      • Threat
        • DUALS(4)
      • Vars
        • B(a);XS(B)::QAR1(G)
        • B(a);::P(A)
      • Refutation
        • P(f);CHECK,XS(E)
    • Try
      • Q(G);
      • Threat
        • QAB(G)
      • Vars
        • P(f);SBLOCK,XS(E)::P(A)
        • P(d);S_CUTB(a)::S(E)
      • Refutation
        • K(b);N_SPINP(c),S_FLIGHT,XS(E)
  • Actual
    • Q(G);
    • Threat
      • QAB(G)
    • Vars
      • K(b);N_SPINP(c),OGATEB,S_FLIGHT,XS(E)::QAB(G)
      • P(f);SBLOCK,XS(E)::P(A)
      • P(d);S_CUTB(a)::S(E)


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).