Problem Display
PID: 284861 (8/6np/5R1R/3K2k1/6P1/5Q2/3b4/8 w - - 0 1)

Jonsson, Gustav

Problemnoter, 1962

8/6np/5R1R/3K2k1/6P1/5Q2/3b4/8

#2

5 + 4


15601 Albrecht-Leiss-Degener Collection 2026
5454 Near Snap 2026

SOLUTION


  • SOUND
  • Sets
    • 1...Be1
      • 2.Qf4#
    • 1...Bc3
      • 2.Qf4#
    • 1...Bb4
      • 2.Qf4#
    • 1...Bf4
      • 2.Qxf4#
    • 1...Ba5
      • 2.Qf4#
    • 1...Sf5
      • 2.Qxf5#
    • 1...Sh5
      • 2.Rxh5#
    • 1...Se6
      • 2.Rh5#
      • 2.Qf5#
    • 1...Se8
      • 2.Rh5#
      • 2.Qf5#
  • Tries
    • 1.Qf2?
      • threat
        • 2.Qh4#
      • 1...Kxg4
        • 2.Qg1#
        • 2.Qh4#
        • 2.Qg2#
      • 1...Be1
        • 2.Qf4#
      • 1...Sf5
        • 2.Qxf5#
      • 1...Sh5!
    • 1.Qe3+?
      • 1...Kxg4
        • 2.Qg1#
      • 1...Bxe3!
    • 1.Qh3?
      • threat
        • 2.Qh4#
      • 1...Sf5
        • 2.Rxf5#
      • 1...Sh5
        • 2.Qxh5#
      • 1...Be1!
  • Keys
    • 1.Qg3!
      • threat
        • 2.Qh4#
      • 1...Be1
        • 2.Qf4#
      • 1...Sf5
        • 2.gxf5#
      • 1...Sh5
        • 2.gxh5#

Anticipated by 18650(1957)

FEATURES


  • Static
    • TYPE = THREAT
    • CHANGED MATES = 2
    • ADDED MATES = 0
    • REMOVED MATES = 4
  • Sets
    • B(a);N_GUARD::QAB1(A)
    • B(a);N_GUARD::QAB1(A),XB(a)
    • S(c);N_GUARD::QAR1(A),XS(c)
    • S(c);N_GUARD::R1(E),XS(c)
  • Tries
    • Try
      • Q(A);
      • Threat
        • QAB1(A)
      • Vars
        • B(a);N_GUARD::QAB1(A)
        • S(c);N_GUARD::QAR1(A),XS(c)
      • Refutation
        • S(c);
    • Try
      • Q(A);CHECK
      • Vars
        • K(b);OGATEB,P-FLIGHT,XP(B)::QAR(A)
      • Refutation
        • B(a);XQ(A)
    • Try
      • Q(A);
      • Threat
        • QAB1(A)
      • Vars
        • S(c);N_GUARD::R1(D),XS(c)
        • S(c);N_GUARD::QAR1(A),XS(c)
      • Refutation
        • B(a);
  • Actual
    • Q(A);
    • Threat
      • QAB1(A)
    • Vars
      • B(a);N_GUARD::QAB1(A)
      • S(c);OGATE::QAR(A)+P(B),XS(c)


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).