MESON Chess Problem Database

Problem Display
PID: 144845 (3b2n1/4N2R/1P3P2/8/4N1kB/3KPq1p/p2Q1P2/3B3n w - - 0 1)

Mackay, Donald

The Observer, 1920

(First published on Sun Aug 1 1920)

3b2n1/4N2R/1P3P2/8/4N1kB/3KPq1p/p2Q1P2/3B3n

#2

11 + 7

14868 Pirnie Collection 2012
15239 Valois Notebooks 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Qxd1
      • 2.Qxd1#
    • 1...Qe2+
      • 2.Bxe2#
      • 2.Qxe2#
    • 1...Sxf2+
      • 2.Sxf2#
    • 1...Sxf6
      • 2.Sxf6#
  • Tries
    • 1.Qa5?
      • threat
        • 2.Qf5#
        • 2.Qg5#
        • 2.Qh5#
      • 1...Qe2+
        • 2.Bxe2#
      • 1...Sxf2+
        • 2.Sxf2#
      • 1...Bxe7
        • 2.Qg5#
        • 2.Qh5#
      • 1...Sxf6
        • 2.Sxf6#
        • 2.Qf5#
        • 2.Qg5#
      • 1...Sxe7
        • 2.Qg5#
        • 2.Qh5#
      • 1...Sh6
        • 2.Qg5#
      • 1...h2
        • 2.Qf5#
      • 1...Sg3
        • 2.Qg5#
      • 1...Qxd1+!
    • 1.Qe2?
      • threat
        • 2.Qxf3#
      • 1...Qxe2+
        • 2.Bxe2#
      • 1...Sxf2+
        • 2.Sxf2#
      • 1...Sh6!
  • Keys
    • 1.Qb4!
      • threat
        • 2.Sd2#
        • 2.Sc3#
        • 2.Sg3#
        • 2.Sc5#
        • 2.Sg5#
        • 2.Sd6#
      • 1...Qxd1+
        • 2.Sd2#
      • 1...Qe2+
        • 2.Bxe2#
      • 1...Sxf2+
        • 2.Sxf2#
      • 1...Bxb6
        • 2.Sc5#
      • 1...Bxe7
        • 2.Sd6#
      • 1...Sxf6
        • 2.Sxf6#
      • 1...Sxe7
        • 2.Sg3#
        • 2.Sd6#
      • 1...Sh6
        • 2.Sg3#
      • 1...h2
        • 2.Sg5#
      • 1...a1Q
        • 2.Sc3#
      • 1...a1B
        • 2.Sc3#
      • 1...Bc7
        • 2.Sd6#
      • 1...Sg3
        • 2.Sxg3#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 9
    • REMOVED MATES = 0
  • Sets
    • Q(c);N_PINP(E),N_SPINQ(c),OGATE,P_PINQ(B),XB(A)::QAB(B),XQ(c)
    • S(a);CHECK,XP(C)::S(F),XS(a)
    • S(g);XP(I)::S(F),XS(g)
  • Tries
    • Try
      • Q(B);
      • Threat
        • DUALS(3)
      • Vars
        • Q(c);CHECK,N_PINP(E),OGATEB::B(A),XQ(c)
        • S(a);CHECK,XP(C)::S(F),XS(a)
        • S(g);::QAR1(B)
        • P(d);::QAB1(B)
        • S(a);::QAR1(B)
      • Refutation
        • Q(c);CHECK,N_PINP(E),N_SPINQ(c),XB(A)
    • Try
      • Q(B);
      • Threat
        • QAB1(B),XQ(c)
      • Vars
        • Q(c);CHECK,N_PINP(E),OGATE,XQ(B)::B(A),XQ(c)
        • S(a);CHECK,XP(C)::S(F),XS(a)
      • Refutation
        • S(g);
  • Actual
    • Q(B);
    • Threat
      • DUALS(6)
    • Vars
      • Q(c);CHECK,N_PINP(E),N_SPINQ(c),XB(A)::QAR(B)+S(F)
      • Q(c);CHECK,N_PINP(E),OGATEB::B(A),XQ(c)
      • S(a);CHECK,XP(C)::QAR(B)+S(F),DCHECK,XS(a)
      • B(f);XP(H)::QAR(B)+S(F)
      • B(f);XS(J)::QAR(B)+S(F)
      • S(g);XP(I)::QAR(B)+S(F),DCHECK,XS(g)
      • S(g);::QAR(B)+S(F)
      • P(d);::QAR(B)+S(F)
      • P(b);::QAR(B)+S(F)
      • B(f);::QAR(B)+S(F)
      • S(a);::QAR(B)+S(F),XS(a)
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).