MESON Chess Problem Database

Problem Display
PID: 65293 (brNK4/Bk1P1Q2/1n6/1B1p4/3P4/8/8/8 w - - 0 1)

Penrose, Lionel Sharples

Good Companions (August), 1921

brNK4/Bk1P1Q2/1n6/1B1p4/3P4/8/8/8

#2

7 + 5

3132 The Good Companion Two-Mover 1922

SOLUTION

  • SOUND
  • Sets
    • 1...Rxc8+
      • 2.dxc8Q#
      • 2.dxc8B#
    • 1...Sa4
      • 2.Qxd5#
    • 1...Sc4
      • 2.Qxd5#
    • 1...Sxd7
      • 2.Qxd5#
      • 2.Qxd7#
    • 1...Sxc8
      • 2.dxc8Q#
      • 2.dxc8S#
      • 2.dxc8B#
      • 2.dxc8R#
  • Tries
    • 1.Ba6+?
      • 1...Kc6
        • 2.Qe6#
        • 2.Qg6#
        • 2.Qf6#
      • 1...Kxa6!
    • 1.Qe6?
      • threat
        • 2.Qxb6#
        • 2.Qc6#
      • 1...Sxd7
        • 2.Ba6#
        • 2.Qxd5#
        • 2.Qxd7#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Sxc8
        • 2.Qa6#
      • 1...Sa4
        • 2.Ba6#
        • 2.Qxd5#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Sc4
        • 2.Ba6#
        • 2.Qxd5#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Rxc8+!
    • 1.Qg6?
      • threat
        • 2.Qxb6#
        • 2.Qc6#
      • 1...Sxd7
        • 2.Ba6#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Sxc8
        • 2.Qa6#
      • 1...Sa4
        • 2.Ba6#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Sc4
        • 2.Ba6#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Rxc8+!
    • 1.Qf4?
      • threat
        • 2.Qc7#
        • 2.Qxb8#
      • 1...Sxd7
        • 2.Qc7#
      • 1...Rxc8+!
    • 1.Qf6?
      • threat
        • 2.Qxb6#
        • 2.Qc6#
      • 1...Sxd7
        • 2.Ba6#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Sxc8
        • 2.Qa6#
      • 1...Sa4
        • 2.Ba6#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Sc4
        • 2.Ba6#
        • 2.Qa6#
        • 2.Qc6#
      • 1...Rxc8+!
  • Keys
    • 1.Ke8!
      • 1...Rxc8+
        • 2.d8S#
      • 1...Kc7
        • 2.d8Q#
      • 1...Sxd7
        • 2.Qxd7#
      • 1...Sxc8
        • 2.d8S#
      • 1...Sa4
        • 2.d8Q#
        • 2.d8R#
      • 1...Sc4
        • 2.d8Q#
        • 2.d8R#

FEATURES

  • Static
    • TYPE = WAITER
    • CHANGED MATES = 0
    • ADDED MATES = 4
    • REMOVED MATES = 2
  • Sets
    • R(e);CHECK,OGATE,XS(F)::PXR(e)=Q
    • S(b);N_GUARD::QAB(E),XP(a)
  • Tries
    • Try
      • B(B);CHECK
      • Refutation
        • K(c);S_FLIGHT,XB(B)
    • Try
      • Q(E);
      • Threat
        • DUALS(2)
      • Vars
        • S(b);OGATE,XS(F)::QAB1(E)
      • Refutation
        • R(e);CHECK,XS(F)
    • Try
      • Q(E);
      • Threat
        • DUALS(2)
      • Vars
        • S(b);OGATE,XS(F)::QAB1(E)
      • Refutation
        • R(e);CHECK,XS(F)
    • Try
      • Q(E);
      • Threat
        • DUALS(2)
      • Vars
        • S(b);XP(D)::QAR1(E)
      • Refutation
        • R(e);CHECK,XS(F)
    • Try
      • Q(E);
      • Threat
        • DUALS(2)
      • Vars
        • S(b);OGATE,XS(F)::QAB1(E)
      • Refutation
        • R(e);CHECK,XS(F)
  • Actual
    • K(G);P-FLIGHT
    • Vars
      • R(e);CHECK,SBLOCK,XS(F)::P=S
      • K(c);P-FLIGHT::P=Q
      • S(b);OGATE,P_SPINS(b),XP(D)::QAR2(E),XS(b)
      • S(b);N_GUARD,SBLOCK,XS(F)::P=S
      • S(b);N_GUARD::P=Q
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