Problem Display
PID: 22405 (8/5N2/2B3k1/7N/8/7K/8/3Q4 w - - 0 1)

Renn, Albert

Schach-Echo, 1969

8/5N2/2B3k1/7N/8/7K/8/3Q4

#2

5 + 1


5454 Near Snap 2007

SOLUTION


  • SOUND
  • Sets
    • 1...Kf5
      • 2.Qg4#
  • Tries
    • 1.Bd5?
      • 1...Kf5
        • 2.Qc2#
        • 2.Qg4#
        • 2.Qb1#
        • 2.Qd3#
      • 1...Kh7!
    • 1.Be8?
      • 1...Kf5
        • 2.Qg4#
      • 1...Kh7!
    • 1.Qc2+?
      • 1...Kxh5
        • 2.Bf3#
        • 2.Qf5#
        • 2.Qh7#
      • 1...Kxf7!
    • 1.Qe2?
      • 1...Kf5
        • 2.Qg4#
        • 2.Qe4#
      • 1...Kxf7
        • 2.Qe8#
      • 1...Kh7!
    • 1.Qg4+?
      • 1...Kh7
        • 2.Sf6#
        • 2.Be4#
        • 2.Qg7#
      • 1...Kxf7!
    • 1.Qb1+?
      • 1...Kxh5
        • 2.Bf3#
        • 2.Qf5#
        • 2.Qh7#
      • 1...Kxf7!
    • 1.Qf1?
      • 1...Kxh5
        • 2.Qf5#
      • 1...Kh7!
    • 1.Qg1+?
      • 1...Kf5
        • 2.Qg4#
      • 1...Kxh5
        • 2.Bf3#
        • 2.Qg4#
        • 2.Qg5#
      • 1...Kh7
        • 2.Sf6#
        • 2.Be4#
        • 2.Qg7#
      • 1...Kxf7!
    • 1.Qd3+?
      • 1...Kxh5
        • 2.Bf3#
        • 2.Qf5#
        • 2.Qh7#
      • 1...Kxf7!
    • 1.Qd4?
      • 1...Kf5
        • 2.Qf6#
        • 2.Qe4#
        • 2.Qg4#
      • 1...Kxh5
        • 2.Qg4#
      • 1...Kh7
        • 2.Qg7#
      • 1...Kxf7!
    • 1.Qd7?
      • 1...Kxh5
        • 2.Qg4#
        • 2.Qf5#
      • 1...Kh7!
  • Keys
    • 1.Qd8!
      • 1...Kf5
        • 2.Qf6#
      • 1...Kxh5
        • 2.Qg5#
      • 1...Kxf7
        • 2.Qe8#
      • 1...Kh7
        • 2.Be4#

This anticipates 10890(1969), 22391(1970)

FEATURES


  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 1
    • ADDED MATES = 3
    • REMOVED MATES = 0
  • Sets
    • K(a);S_FLIGHT::QAB1(A)
  • Tries
    • Try
      • B(D);
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • B(D);
      • Vars
        • K(a);S_FLIGHT::QAB1(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • Q(A);CHECK
      • Refutation
        • K(a);S_FLIGHT,XS(E)
    • Try
      • Q(A);
      • Vars
        • K(a);OGATEB,S_FLIGHT,XS(E)::QAB1(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • Q(A);CHECK
      • Refutation
        • K(a);S_FLIGHT,XS(E)
    • Try
      • Q(A);CHECK
      • Refutation
        • K(a);S_FLIGHT,XS(E)
    • Try
      • Q(A);
      • Vars
        • K(a);S_FLIGHT,XS(C)::QAR2(A)
      • Refutation
        • K(a);S_FLIGHT
    • Try
      • Q(A);CHECK
      • Vars
        • K(a);S_FLIGHT::QAB1(A)
      • Refutation
        • K(a);S_FLIGHT,XS(E)
    • Try
      • Q(A);CHECK
      • Refutation
        • K(a);S_FLIGHT,XS(E)
    • Try
      • Q(A);
      • Vars
        • K(a);S_FLIGHT,XS(C)::QAB1(A)
        • K(a);S_FLIGHT::QAR1(A)
      • Refutation
        • K(a);S_FLIGHT,XS(E)
    • Try
      • Q(A);
      • Refutation
        • K(a);S_FLIGHT
  • Actual
    • Q(A);
    • Vars
      • K(a);S_FLIGHT::QAR1(A)
      • K(a);S_FLIGHT,XS(C)::QAR1(A)
      • K(a);OGATEB,S_FLIGHT,XS(E)::QAB1(A)
      • K(a);S_FLIGHT::B(D)


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).