Problem Display
PID: 21141 (3NkN2/4b3/4Q3/8/1p6/1K6/8/8 w - - 0 1)

Williams, Philip Hamilton

Chess Amateur (The), 1917

3NkN2/4b3/4Q3/8/1p6/1K6/8/8

#2

4 + 3


3360 Simple Two-move Themes 1924
3295 Einfuhrung in die Welt des Schachproblem 1984
5454 Near Snap 2008
3713 Snap 2019

SOLUTION


  • SOUND
  • Sets
    • 1...Kxd8
      • 2.Qd7#
    • 1...Kxf8
      • 2.Qf7#
  • Tries
    • 1.Ka2?
      • 1...Kxd8
        • 2.Qd7#
      • 1...Kxf8
        • 2.Qf7#
      • 1...b3+!
    • 1.Kb2?
      • 1...Kxd8
        • 2.Qd7#
      • 1...Kxf8
        • 2.Qf7#
      • 1...b3!
    • 1.Kc2?
      • 1...Kxd8
        • 2.Qd7#
      • 1...Kxf8
        • 2.Qf7#
      • 1...b3+!
    • 1.Ka4?
      • 1...Kxd8
        • 2.Qd7#
      • 1...Kxf8
        • 2.Qf7#
      • 1...b3!
    • 1.Kc4?
      • 1...Kxd8
        • 2.Qd7#
      • 1...Kxf8
        • 2.Qf7#
      • 1...b3!
    • 1.Qc6+?
      • 1...Kxd8
        • 2.Se6#
        • 2.Qd7#
      • 1...Kxf8!
    • 1.Qg6+?
      • 1...Kxf8
        • 2.Se6#
        • 2.Qf7#
      • 1...Kxd8!
  • Keys
    • 1.Qe5!
      • 1...Kxd8
        • 2.Qb8#
      • 1...Kxf8
        • 2.Qh8#

Anticipated by 206996(1859), 222837(1884), 193956(1916)

This anticipates 227663(1926), 76800(1945), 142699(1954), 105209(1958), 138156(1962), 217452(1992)

This is after 71194

FEATURES


  • Static
    • TYPE = MUTATE
    • CHANGED MATES = 2
    • ADDED MATES = 0
    • REMOVED MATES = 0
  • Sets
    • K(c);N_SPINB(b),P-FLIGHT,XS(C)::QAR1(B)
    • K(c);N_SPINB(b),P-FLIGHT,XS(D)::QAR1(B)
  • Tries
    • Try
      • K(A);S_FLIGHT
      • Vars
        • K(c);N_SPINB(b),P-FLIGHT,XS(C)::QAR1(B)
        • K(c);N_SPINB(b),P-FLIGHT,XS(D)::QAR1(B)
      • Refutation
        • P(a);CHECK
    • Try
      • K(A);P-FLIGHT
      • Vars
        • K(c);N_SPINB(b),P-FLIGHT,XS(C)::QAR1(B)
        • K(c);N_SPINB(b),P-FLIGHT,XS(D)::QAR1(B)
      • Refutation
        • P(a);
    • Try
      • K(A);S_FLIGHT
      • Vars
        • K(c);N_SPINB(b),P-FLIGHT,XS(C)::QAR1(B)
        • K(c);N_SPINB(b),P-FLIGHT,XS(D)::QAR1(B)
      • Refutation
        • P(a);CHECK
    • Try
      • K(A);S_FLIGHT
      • Vars
        • K(c);N_SPINB(b),P-FLIGHT,XS(C)::QAR1(B)
        • K(c);N_SPINB(b),P-FLIGHT,XS(D)::QAR1(B)
      • Refutation
        • P(a);
    • Try
      • K(A);S_FLIGHT
      • Vars
        • K(c);N_SPINB(b),P-FLIGHT,XS(C)::QAR1(B)
        • K(c);N_SPINB(b),P-FLIGHT,XS(D)::QAR1(B)
      • Refutation
        • P(a);
    • Try
      • Q(B);CHECK,N_PINB(b)
      • Refutation
        • K(c);P-FLIGHT,XS(D)
    • Try
      • Q(B);CHECK,N_PINB(b)
      • Refutation
        • K(c);P-FLIGHT,XS(C)
  • Actual
    • Q(B);
    • Vars
      • K(c);N_SPINB(b),OGATEB,P-FLIGHT,XS(C)::QAR2(B)
      • K(c);N_SPINB(b),OGATEB,P-FLIGHT,XS(D)::QAR2(B)


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).