MESON Chess Problem Database

Problem Display
PID: 15321 (Kn4nN/1Q3b2/2Pk1p2/p7/3P1N2/8/q6B/2R4B w - - 0 1)

Froberg, Johan Hilding Laurentius

2nd HM., Neue Zurcher Zeitung, 1982

Kn4nN/1Q3b2/2Pk1p2/p7/3P1N2/8/q6B/2R4B

#2

9 + 7

5454 Near Snap 2026

SOLUTION

  • SOUND
  • Sets
    • 1...Qb1
      • 2.Sxf7#
    • 1...Qa1
      • 2.Sxf7#
    • 1...Qb2
      • 2.Sxf7#
    • 1...Qc2
      • 2.Sxf7#
    • 1...Qd2
      • 2.Sxf7#
    • 1...Qe2
      • 2.Sxf7#
    • 1...Qf2
      • 2.Sxf7#
    • 1...Qg2
      • 2.Sxf7#
    • 1...Qxh2
      • 2.Sxf7#
    • 1...Qa3
      • 2.Sxf7#
    • 1...Qa4
      • 2.Sxf7#
    • 1...Be6
      • 2.Se2#
    • 1...Sa6
      • 2.Qd7#
    • 1...Sxc6
      • 2.Rxc6#
    • 1...Sd7
      • 2.Qxd7#
    • 1...Se7
      • 2.Qxb8#
  • Tries
    • 1.Kxb8?
      • threat
        • 2.Qc7#
        • 2.Qd7#
      • 1...Qb1
        • 2.Sxf7#
      • 1...Qe6
        • 2.Qc7#
      • 1...Qb2
        • 2.Sxf7#
      • 1...Be6
        • 2.Se2#
        • 2.Qc7#
      • 1...Be8
        • 2.Qc7#
      • 1...Qb3!
    • 1.Sh5+?
      • 1...Ke6
        • 2.Sg7#
      • 1...Qxh2!
    • 1.Qb4+?
      • 1...Kc7
        • 2.Qxb8#
      • 1...axb4+!
  • Keys
    • 1.Re1!
      • threat
        • 2.Qxb8#
      • 1...Sxc6
        • 2.Qxc6#
      • 1...Qb3
        • 2.Sd3#
      • 1...Qb1
        • 2.Sd3#
        • 2.Sh3#
        • 2.Sd5#
        • 2.Sh5#
        • 2.Se6#
        • 2.Sfg6#
        • 2.Sxf7#
      • 1...Qd5
        • 2.Sxd5#
      • 1...Qe6
        • 2.Sxe6#
      • 1...Qb2
        • 2.Sxf7#
      • 1...Qe2
        • 2.Sxf7#
      • 1...Qg2
        • 2.Sxf7#
      • 1...Bd5
        • 2.Sg2#
      • 1...Be6
        • 2.Se2#
      • 1...Sa6
        • 2.Qd7#
      • 1...Sd7
        • 2.Qxd7#

This anticipates 285279(1985)

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 4
    • REMOVED MATES = 9
  • Sets
    • Q(a);N_GUARD::S(I),XB(e)
    • Q(a);N_GUARD,XB(C)::S(I),XB(e)
    • B(e);SBLOCK::B(C)+S(E)
    • S(f);N_GUARD::QAR1(G)
    • S(f);OGATE,XP(F)::R1(A),XS(f)
    • S(f);N_GUARD::QAR1(G),XS(f)
    • S(g);SBLOCK::QAB(G),XS(f)
  • Tries
    • Try
      • K(H);P-FLIGHT,XS(f)
      • Threat
        • DUALS(2)
      • Vars
        • Q(a);N_GUARD,P_PINQ(G)::S(I),XB(e)
        • Q(a);::QAB1(G)
        • B(e);::QAB1(G)
      • Refutation
        • Q(a);P_PINQ(G)
    • Try
      • S(E);CHECK
      • Vars
        • K(c);P-FLIGHT::S(E)
      • Refutation
        • Q(a);XB(C)
    • Try
      • Q(G);CHECK
      • Vars
        • K(c);S_FLIGHT::QAB1(G),XS(f)
      • Refutation
        • P(b);CHECK,XQ(G)
  • Actual
    • R(A);
    • Threat
      • QAB(G),XS(f)
    • Vars
      • S(f);OGATE,XP(F)::QAR1(G),XS(f)
      • Q(a);N_GUARD::B(C)+S(E)
      • Q(a);N_GUARD::B(C)+S(E),XQ(a)
      • Q(a);N_GUARD::S(I),XB(e)
      • B(e);SBLOCK::B(C)+S(E)
      • S(f);N_GUARD::QAR1(G)
      • S(f);N_GUARD::QAR1(G),XS(f)
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