MESON Chess Problem Database

Problem Display
PID: 18920 (6QK/8/8/1p6/6R1/qNkN4/7R/5B2 w - - 0 1)

Larsen, Karl Adolf Koefoed

4th HM., Israel Ring Ty., 1959

6QK/8/8/1p6/6R1/qNkN4/7R/5B2

#2

7 + 3

3310 2345 Chess Problems 1997

SOLUTION

  • SOUND
  • Sets
    • 1...Qxb3
      • 2.Qg7#
    • 1...b4
      • 2.Qc4#
  • Tries
    • 1.Sd4?
      • threat
        • 2.Sxb5#
        • 2.Rc2#
      • 1...Qc1
        • 2.Sxb5#
        • 2.Qb3#
        • 2.Qc8#
      • 1...Qb2
        • 2.Qc8#
      • 1...Qb4
        • 2.Rc2#
      • 1...Qc5
        • 2.Rc2#
        • 2.Qb3#
      • 1...Qa2
        • 2.Sxb5#
      • 1...Qb3
        • 2.Qxb3#
      • 1...Qa5
        • 2.Rc2#
        • 2.Qb3#
      • 1...Qa6
        • 2.Rc2#
        • 2.Qb3#
      • 1...b4
        • 2.Sb5#
        • 2.Rc2#
        • 2.Qc8#
      • 1...Qa4!
    • 1.Qc8+?
      • 1...Kxb3
        • 2.Qc2#
      • 1...Qc5!
  • Keys
    • 1.Sb4!
      • threat
        • 2.Rc2#
      • 1...Qxb4
        • 2.Rg3#
      • 1...Qxb3
        • 2.Qg7#
      • 1...Qc1
        • 2.Sa2#
      • 1...Qb2
        • 2.Rh3#
      • 1...Qa2
        • 2.Sxa2#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 4
    • REMOVED MATES = 1
  • Sets
    • Q(a);SBLOCK,XS(C)::QAB(F)
    • P(c);N_GUARD::QAR1(F)
  • Tries
    • Try
      • S(C);
      • Threat
        • DUALS(2)
      • Vars
        • Q(a);N_GUARD::QAR(F)
        • Q(a);::R1(B)
        • Q(a);::S(C),XP(c)
        • Q(a);N_GUARD::QAR1(F),XQ(a)
      • Refutation
        • Q(a);
    • Try
      • Q(F);CHECK
      • Vars
        • K(b);OGATE,P-FLIGHT,XS(C)::QAB1(F)
      • Refutation
        • Q(a);P_SPINQ(a)
  • Actual
    • S(D);
    • Threat
      • R1(B)
    • Vars
      • Q(a);SBLOCK,XS(D)::R(E)
      • Q(a);SBLOCK,XS(C)::QAB(F)
      • Q(a);N_GUARD::S(D)
      • Q(a);SBLOCK::R(B)
      • Q(a);N_GUARD::S(D),XQ(a)
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