MESON Chess Problem Database

Problem Display
PID: 107680 (8/8/6Qp/2p1N2r/2K1pk2/5P2/8/6B1 w - - 0 1)

Balslev, Ole

Stella Polaris, 1968

8/8/6Qp/2p1N2r/2K1pk2/5P2/8/6B1

#2

5 + 5

6490 yacpdb 2009
5454 Near Snap 2018

SOLUTION

  • SOUND
  • Sets
    • 1...Rxe5
      • 2.Qg4#
    • 1...exf3
      • 2.Sd3#
  • Tries
    • 1.Be3+?
      • 1...Kxe5
        • 2.f4#
      • 1...Kxe3!
    • 1.Qxe4+?
      • 1...Kg3
        • 2.Qg4#
      • 1...Kg5!
    • 1.Qxh5?
      • 1...Kg3
        • 2.Qg4#
        • 2.Qh2#
      • 1...e3
        • 2.Bh2#
      • 1...exf3!
  • Keys
    • 1.Bf2!
      • 1...Kxe5
        • 2.Bg3#
      • 1...Rxe5
        • 2.Qg4#
      • 1...exf3
        • 2.Sd3#
      • 1...Rh1
        • 2.Qf6#
      • 1...Rh2
        • 2.Qf6#
      • 1...Rh3
        • 2.Qf6#
      • 1...Rh4
        • 2.Qf6#
      • 1...Rf5
        • 2.Qg3#
      • 1...Rg5
        • 2.Qxe4#
      • 1...e3
        • 2.Bg3#

Anticipated by 175717(1898), 178563(1951)

FEATURES

  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 0
    • ADDED MATES = 8
    • REMOVED MATES = 0
  • Sets
    • R(d);SBLOCK,XS(D)::QAR1(E)
    • P(a);N_GUARD,SBLOCK,XP(B)::S(D)
  • Tries
    • Try
      • B(A);CHECK
      • Vars
        • K(b);OGATE,S_FLIGHT,XS(D)::P(B)
      • Refutation
        • K(b);S_FLIGHT,XB(A)
    • Try
      • Q(E);CHECK,XP(a)
      • Vars
        • K(b);OGATE,S_FLIGHT::QAR1(E)
      • Refutation
        • K(b);S_FLIGHT
    • Try
      • Q(E);XR(d)
      • Vars
        • P(a);SBLOCK::B(A)
      • Refutation
        • P(a);XP(B)
  • Actual
    • B(A);
    • Vars
      • K(b);S_FLIGHT,XS(D)::B(A)
      • R(d);SBLOCK,XS(D)::QAR1(E)
      • P(a);N_GUARD,SBLOCK,XP(B)::S(D)
      • R(d);N_GUARD::QAR2(E)
      • R(d);SBLOCK::QAB1(E)
      • R(d);SBLOCK::QAR1(E),XP(a)
      • P(a);SBLOCK::B(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).