MESON Chess Problem Database

Problem Display
PID: 79250 (8/7p/8/3B1K2/4N3/8/5Q2/1q5k w - - 0 1)

Ahlheim, Karl-Heinz

Europe Echecs, 1962

8/7p/8/3B1K2/4N3/8/5Q2/1q5k

#2

4 + 3

5454 Near Snap 2009
15148 Sadier Collection 2014

SOLUTION

  • SOUND
  • Sets
    • 1...Qa2
      • 2.Sg3#
    • 1...Qxe4+
      • 2.Bxe4#
    • 1...Qa1
      • 2.Sd2#
      • 2.Sc3#
      • 2.Sg3#
      • 2.Sc5#
      • 2.Sg5#
      • 2.Sd6#
      • 2.Sf6#
    • 1...Qc1
      • 2.Sd2#
      • 2.Sc3#
      • 2.Sg3#
      • 2.Sc5#
      • 2.Sg5#
      • 2.Sd6#
      • 2.Sf6#
    • 1...Qd1
      • 2.Sg3#
    • 1...Qe1
      • 2.Sg3#
    • 1...Qf1
      • 2.Sg3#
    • 1...Qg1
      • 2.Sg3#
    • 1...Qb2
      • 2.Sd2#
      • 2.Sc3#
      • 2.Sg3#
      • 2.Sc5#
      • 2.Sg5#
      • 2.Sd6#
      • 2.Sf6#
    • 1...Qb3
      • 2.Sg3#
    • 1...Qb4
      • 2.Sg3#
    • 1...Qb5
      • 2.Sg3#
      • 2.Sc5#
    • 1...Qb6
      • 2.Sd2#
      • 2.Sc3#
      • 2.Sg3#
      • 2.Sc5#
      • 2.Sg5#
      • 2.Sd6#
      • 2.Sf6#
    • 1...Qb7
      • 2.Sg3#
    • 1...Qb8
      • 2.Sd2#
      • 2.Sc3#
      • 2.Sg3#
      • 2.Sc5#
      • 2.Sg5#
      • 2.Sd6#
      • 2.Sf6#
  • Tries
    • 1.Kf4?
      • threat
        • 2.Sg3#
      • 1...Qxe4+
        • 2.Bxe4#
      • 1...Qc1+
        • 2.Sd2#
      • 1...Qb8+
        • 2.Sd6#
      • 1...Qb4!
    • 1.Ke5?
      • threat
        • 2.Sg3#
      • 1...Qxe4+
        • 2.Bxe4#
      • 1...Qa1+
        • 2.Sc3#
      • 1...Qb2+
        • 2.Sc3#
      • 1...Qb8+
        • 2.Sd6#
      • 1...Qe1!
    • 1.Kg5?
      • threat
        • 2.Sg3#
      • 1...Qc1+
        • 2.Sd2#
      • 1...Qxe4
        • 2.Bxe4#
      • 1...h6+!
    • 1.Ke6?
      • threat
        • 2.Sg3#
      • 1...Qxe4+
        • 2.Bxe4#
      • 1...Qb6+
        • 2.Sd6#
      • 1...Qe1!
  • Keys
    • 1.Kf6!
      • threat
        • 2.Sg3#
      • 1...Qa1+
        • 2.Sc3#
      • 1...Qb2+
        • 2.Sc3#
      • 1...Qb6+
        • 2.Sd6#
      • 1...Qxe4
        • 2.Bxe4#

This anticipates 107156(1967), 23549(1971), 262360(1985)

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 8
  • Sets
    • Q(a);N_PINS(B)::B(C)+S(B),DCHECK
    • Q(a);CHECK,OGATE,P_SPINQ(a),XS(B)::B(C),XQ(a)
    • Q(a);N_PINS(B),P_PINQ(A)::B(C)+S(B),DCHECK
  • Tries
    • Try
      • K(D);N_SPINS(B),P-FLIGHT
      • Threat
        • B(C)+S(B),DCHECK
      • Vars
        • Q(a);CHECK,OGATE,P_SPINQ(a),XS(B)::B(C),XQ(a)
        • Q(a);CHECK,N_GUARD::B(C)+S(B)
      • Refutation
        • Q(a);P_PINS(B)
    • Try
      • K(D);N_SPINS(B),P-FLIGHT
      • Threat
        • B(C)+S(B),DCHECK
      • Vars
        • Q(a);CHECK,OGATE,P_SPINQ(a),XS(B)::B(C),XQ(a)
        • Q(a);CHECK,N_GUARD,SBLOCK::B(C)+S(B)
        • Q(a);CHECK,N_GUARD::B(C)+S(B)
      • Refutation
        • Q(a);P_PINS(B)
    • Try
      • K(D);N_SPINS(B),P-FLIGHT
      • Threat
        • B(C)+S(B),DCHECK
      • Vars
        • Q(a);CHECK,N_GUARD::B(C)+S(B)
        • Q(a);OGATE,P_SPINQ(a),XS(B)::B(C),XQ(a)
      • Refutation
        • P(c);CHECK
    • Try
      • K(D);N_SPINS(B),S_FLIGHT
      • Threat
        • B(C)+S(B),DCHECK
      • Vars
        • Q(a);CHECK,OGATE,P_SPINQ(a),XS(B)::B(C),XQ(a)
        • Q(a);CHECK,N_GUARD::B(C)+S(B)
      • Refutation
        • Q(a);P_PINS(B)
  • Actual
    • K(D);N_SPINS(B),P-FLIGHT
    • Threat
      • B(C)+S(B),DCHECK
    • Vars
      • Q(a);CHECK,N_GUARD,SBLOCK::B(C)+S(B)
      • Q(a);CHECK,N_GUARD::B(C)+S(B)
      • Q(a);OGATE,P_SPINQ(a),XS(B)::B(C),XQ(a)
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