MESON Chess Problem Database

Problem Display
PID: 230832 (3N1nR1/6P1/q5kr/3B1p1p/2b2Q2/6PK/r2Rp3/b1B5 w - - 0 1)

Podushkin, Sergey

Stella Polaris, 1968

3N1nR1/6P1/q5kr/3B1p1p/2b2Q2/6PK/r2Rp3/b1B5

#2

9 + 10

SOLUTION

  • SOUND
  • Sets
    • 1...Kf6
      • 2.gxf8Q#
    • 1...Kh7
      • 2.gxf8S#
    • 1...Qf6
      • 2.gxf8S#
    • 1...Bf6
      • 2.gxf8S#
  • Tries
    • 1.Rxa2?
      • threat
        • 2.Qxh6#
      • 1...Kf6
        • 2.gxf8Q#
      • 1...Kh7
        • 2.gxf8S#
      • 1...Rh7
        • 2.Qg5#
      • 1...Rh8!
    • 1.Rc2?
      • threat
        • 2.Qxh6#
      • 1...Kf6
        • 2.gxf8Q#
      • 1...Kh7
        • 2.gxf8S#
      • 1...Rh7
        • 2.Qg5#
      • 1...Rh8!
    • 1.Rd4?
      • threat
        • 2.Qxh6#
      • 1...Kf6
        • 2.gxf8Q#
      • 1...Kh7
        • 2.gxf8S#
      • 1...Rh8
        • 2.gxh8Q#
      • 1...Rh7
        • 2.Qg5#
      • 1...Rd2!
    • 1.Qg5+?
      • 1...Kh7
        • 2.Rh8#
        • 2.gxf8S#
      • 1...Kxg5!
    • 1.gxf8Q+?
      • 1...Bg7
        • 2.Rxg7#
        • 2.Qxg7#
        • 2.Q4xf5#
        • 2.Q8xf5#
      • 1...Kh7!
    • 1.gxf8R+?
      • 1...Bg7
        • 2.Qxf5#
      • 1...Kh7!
  • Keys
    • 1.Rb2!
      • threat
        • 2.Qxh6#
      • 1...Kf6
        • 2.gxf8Q#
      • 1...Kh7
        • 2.gxf8S#
      • 1...Rh8
        • 2.gxh8Q#
      • 1...Rh7
        • 2.Qg5#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 2
    • REMOVED MATES = 2
  • Sets
    • K(h);P-FLIGHT,P_SPINP(e)::PXS(j)=Q
    • K(h);S_FLIGHT::PXS(j)=S
    • Q(g);SBLOCK::PXS(j)=S
    • B(a);N_GUARD,SBLOCK::PXS(j)=S
  • Tries
    • Try
      • R(B);XR(b)
      • Threat
        • QAR1(E),XR(i)
      • Vars
        • K(h);P-FLIGHT,P_SPINP(e)::PXS(j)=Q
        • K(h);S_FLIGHT::PXS(j)=S
        • R(i);SBLOCK::QAR1(E)
      • Refutation
        • R(i);
    • Try
      • R(B);
      • Threat
        • QAR1(E),XR(i)
      • Vars
        • K(h);P-FLIGHT,P_SPINP(e)::PXS(j)=Q
        • K(h);S_FLIGHT::PXS(j)=S
        • R(i);SBLOCK::QAR1(E)
      • Refutation
        • R(i);
    • Try
      • R(B);
      • Threat
        • QAR1(E),XR(i)
      • Vars
        • K(h);P-FLIGHT,P_SPINP(e)::PXS(j)=Q
        • K(h);S_FLIGHT::PXS(j)=S
        • R(i);OGATE::PXR(i)=Q
        • R(i);SBLOCK::QAR1(E)
      • Refutation
        • R(b);
    • Try
      • Q(E);CHECK
      • Refutation
        • K(h);P-FLIGHT,XQ(E)
    • Try
      • P(G);CHECK,XS(j)
      • Refutation
        • K(h);S_FLIGHT
    • Try
      • P(G);CHECK,XS(j)
      • Vars
        • B(a);P_SPINB(a)::QAB1(E),XP(e)
      • Refutation
        • K(h);S_FLIGHT
  • Actual
    • R(B);
    • Threat
      • QAR1(E),XR(i)
    • Vars
      • K(h);P-FLIGHT,P_SPINP(e)::PXS(j)=Q
      • K(h);S_FLIGHT::PXS(j)=S
      • R(i);OGATE::PXR(i)=Q
      • R(i);SBLOCK::QAR1(E)
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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).