MESON Chess Problem Database

Problem Display
PID: 8139 (KB4B1/3P4/2pPNb2/2NkqP1R/p1pp3R/4p1r1/8/1Q6 w - - 0 1)

Backe, Espen

The Problemist, 1995

KB4B1/3P4/2pPNb2/2NkqP1R/p1pp3R/4p1r1/8/1Q6

#2

11 + 9

SOLUTION

  • SOUND
  • Sets
    • 1...Qxd6
      • 2.Qe4#
    • 1...Qe4
      • 2.Qxe4#
    • 1...Qxf5
      • 2.Qe4#
    • 1...c3
      • 2.Qa2#
  • Tries
    • 1.Sxa4?
      • threat
        • 2.Sb6#
        • 2.Sf4#
      • 1...Qxd6
        • 2.Qe4#
      • 1...Qxf5
        • 2.Qe4#
      • 1...Qxe6
        • 2.Qe4#
      • 1...Rxg8
        • 2.Sb6#
      • 1...Qe4
        • 2.Qxe4#
      • 1...c5
        • 2.Qb7#
      • 1...Bd8
        • 2.Sf4#
      • 1...d3
        • 2.Sb6#
      • 1...Qf4!
    • 1.Sa6?
      • threat
        • 2.Sb4#
        • 2.Sf4#
      • 1...Qxd6
        • 2.Qe4#
      • 1...Qxf5
        • 2.Qe4#
      • 1...Qxe6
        • 2.Qe4#
      • 1...Rxg8
        • 2.Sb4#
      • 1...Qe4
        • 2.Qxe4#
      • 1...c3
        • 2.Sf4#
        • 2.Qa2#
      • 1...c5
        • 2.Qb7#
      • 1...d3
        • 2.Sb4#
      • 1...Qf4!
    • 1.Sc7+?
      • 1...Kxc5
        • 2.Sa6#
      • 1...Kxd6!
  • Keys
    • 1.Sd3!
      • threat
        • 2.Sb4#
      • 1...Qxd6
        • 2.Sc7#
      • 1...Qxf5
        • 2.Sg7#
      • 1...Qxe6
        • 2.Bxe6#
      • 1...cxd3
        • 2.Qa2#
      • 1...Qf4
        • 2.Sg5#
      • 1...c3
        • 2.Qa2#
      • 1...c5
        • 2.Qb7#
      • 1...Qe4
        • 2.Sef4#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 3
    • ADDED MATES = 4
    • REMOVED MATES = 0
  • Sets
    • Q(g);N_GUARD,XP(F)::QAB1(A)
    • Q(g);N_GUARD::QAB1(A),XQ(g)
    • Q(g);N_GUARD,P_SPINQ(g),XP(D)::QAB1(A)
    • P(d);OGATEB::QAB(A)
  • Tries
    • Try
      • S(C);XP(c)
      • Threat
        • DUALS(2)
      • Vars
        • Q(g);N_GUARD,XP(F)::QAB1(A)
        • Q(g);N_GUARD,P_SPINQ(g),XP(D)::QAB1(A)
        • Q(g);N_GUARD,P_SPINQ(g),XS(G)::QAB1(A)
        • R(b);P_PINB(J),XB(K)::S(C)
        • Q(g);N_GUARD::QAB1(A),XQ(g)
        • P(h);OGATEB::QAB(A)
        • B(i);::B(K)+S(G),DCHECK
        • P(e);::S(C)
      • Refutation
        • Q(g);
    • Try
      • S(C);
      • Threat
        • DUALS(2)
      • Vars
        • Q(g);N_GUARD,XP(F)::QAB1(A)
        • Q(g);N_GUARD,P_SPINQ(g),XP(D)::QAB1(A)
        • Q(g);N_GUARD,P_SPINQ(g),XS(G)::QAB1(A)
        • R(b);P_PINB(J),XB(K)::S(C)
        • Q(g);N_GUARD::QAB1(A),XQ(g)
        • P(h);OGATEB::QAB(A)
        • P(e);::S(C)
      • Refutation
        • Q(g);
    • Try
      • S(G);CHECK
      • Vars
        • K(f);P-FLIGHT,XS(C)::S(G)
      • Refutation
        • K(f);P-FLIGHT,XP(F)
  • Actual
    • S(C);
    • Threat
      • S(C)
    • Vars
      • Q(g);SBLOCK,XP(F)::B(K)+S(G),DCHECK
      • Q(g);N_GUARD,P_SPINQ(g),XP(D)::B(K)+S(G)
      • Q(g);OGATE,P_SPINQ(g),XS(G)::B(K),XQ(g)
      • P(d);OGATEB,XS(C)::QAB(A)
      • Q(g);N_GUARD::B(K)+S(G)
      • P(d);OGATEB::QAB(A)
      • P(h);OGATEB::QAB(A)
      • Q(g);SBLOCK::B(K)+S(G),DCHECK
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