Problem Display
PID: 21689 (3R3K/8/5Q2/8/5N2/1B6/2PB4/1qbk4 w - - 0 1)

White, Alain Campbell

Good Companions (March), 1920

3R3K/8/5Q2/8/5N2/1B6/2PB4/1qbk4

#2

7 + 3


3530 Het Half Pin Thema (II) 0000
3132 The Good Companion Two-Mover 1922
3391 Het Half Pin Thema 1924
3360 Simple Two-move Themes 1924
5501 Chess Cameos 1936
56 The Problemist 1937
56 The Problemist 1938
5089 The Enjoyment of Chess Problems 1943
5064 100 Years of the American Two-move Chess Problem 1962
5066 Classic Chess Problems by Pioneer Composers 1970
3098 FIDE Album (1914-1944) (I) 1971
5007 Zadachi i Etyudi 1995
3310 2345 Chess Problems 1997
5503 ISC 2009
5454 Near Snap 2014

SOLUTION


  • SOUND
  • Sets
    • 1...Qa1
      • 2.c3#
      • 2.c4#
  • Tries
    • 1.Bxc1+?
      • 1...Kxc1
        • 2.Se2#
      • 1...Ke1!
  • Keys
    • 1.Qa1!
      • 1...Qxa1+
        • 2.c3#
      • 1...Qb2+
        • 2.Bc3#
      • 1...Bb2+
        • 2.c3#
      • 1...Qxc2
        • 2.Bc3#
        • 2.Bb4#
        • 2.Ba5#
        • 2.Qxc1#
      • 1...Qxb3
        • 2.Qxc1#
      • 1...Bxd2
        • 2.Qxb1#
      • 1...Qa2
        • 2.Bc3#
        • 2.Bb4#
        • 2.Ba5#
        • 2.Qxc1#
      • 1...Ba3
        • 2.c3#
        • 2.c4#

This anticipates 16935(1944)

FEATURES


  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 0
    • ADDED MATES = 5
    • REMOVED MATES = 0
  • Sets
  • Tries
    • Try
      • B(B);CHECK,XB(b)
      • Vars
        • K(c);P-FLIGHT,XB(B)::S(D)
      • Refutation
        • K(c);P-FLIGHT
  • Actual
    • Q(E);
    • Vars
      • Q(a);CHECK,N_GUARD,XQ(E)::B(C)+P(A)
      • Q(a);CHECK,P_SPINB(b)::R(F)+B(B)
      • B(b);CHECK,P_SPINQ(a)::B(C)+P(A)
      • Q(a);OGATE,P_SPINB(b),XB(C)::QAR1(E),XB(b)
      • B(b);OGATEB,P_SPINB(b),P_SPINQ(a),XB(B)::QAR2(E),XQ(a)


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).