Problem Display
PID: 211346 (8/8/5N2/5k2/7K/2B5/8/Q7 w - - 0 1)

Inostroza, Sergio

The Problemist, 1986

8/8/5N2/5k2/7K/2B5/8/Q7

#2

4 + 1


5454 Near Snap 2021

SOLUTION


  • SOUND
  • Tries
    • 1.Qb1+?
      • 1...Kf4
        • 2.Qe4#
      • 1...Ke6!
    • 1.Qe1?
      • threat
        • 2.Qe4#
      • 1...Kf4
        • 2.Qf2#
        • 2.Qe4#
      • 1...Kg6!
    • 1.Qg1?
      • threat
        • 2.Qg4#
      • 1...Kf4
        • 2.Qf2#
      • 1...Ke6!
    • 1.Qa2?
      • 1...Kf4
        • 2.Qf2#
      • 1...Kg6!
    • 1.Qa4?
      • threat
        • 2.Qe4#
        • 2.Qg4#
      • 1...Ke6
        • 2.Qd7#
      • 1...Kg6!
  • Keys
    • 1.Qa7!
      • 1...Kf4
        • 2.Qf2#
      • 1...Ke6
        • 2.Qd7#
      • 1...Kg6
        • 2.Qh7#

Anticipated by 206947(1859), 4506(1873), 32680(1873), 218488(1882), 218611(1882), 24321(1885), 181144(1904), 182379(1906), 109336(1920), 22076(1924), 206740(1925), 227725(1926), 76425(1929), 46372(1941), 18804(1958), 218807(1976), 133136(1983)

This anticipates 184446(2000), 47757(2003), 67253(2006), 232491(2012), 235007(2019)

FEATURES


  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 0
  • Sets
  • Tries
    • Try
      • Q(A);CHECK
      • Vars
        • K(a);P-FLIGHT::QAR1(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • Q(A);
      • Threat
        • QAB1(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • Q(A);
      • Threat
        • QAB1(A)
      • Vars
        • K(a);P-FLIGHT::QAR2(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • Q(A);
      • Vars
        • K(a);P-FLIGHT::QAR2(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • Q(A);
      • Threat
        • DUALS(2)
      • Vars
        • K(a);S_FLIGHT::QAB1(A)
      • Refutation
        • K(a);S_FLIGHT
  • Actual
    • Q(A);
    • Vars
      • K(a);P-FLIGHT::QAR2(A)
      • K(a);S_FLIGHT::QAB1(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).