MESON Chess Problem Database

Problem Display
PID: 207897 (1R1B4/1b1npN2/pn2N3/Pkp5/R3P3/P7/4K3/3Q4 w - - 0 1)

Collard, FS

The Observer, 1955

(First published on Sun Mar 13 1955)

1R1B4/1b1npN2/pn2N3/Pkp5/R3P3/P7/4K3/3Q4

#2

10 + 7

15239 Valois Notebooks 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Bc6
      • 2.Sc7#
      • 2.Qb3#
    • 1...Sc4
      • 2.Qxd7#
    • 1...Sa8
      • 2.Qxd7#
    • 1...Sc8
      • 2.Qxd7#
  • Tries
    • 1.Rxb7?
      • threat
        • 2.Qxd7#
      • 1...Se5
        • 2.Rxb6#
      • 1...Sf6
        • 2.Rxb6#
      • 1...Sb8
        • 2.Rxb6#
      • 1...Sf8
        • 2.Rxb6#
      • 1...Kc6!
  • Keys
    • 1.Rc4!
      • 1...Kxc4
        • 2.Qd3#
      • 1...Kxa5
        • 2.Qa4#
      • 1...Kc6
        • 2.Sd4#
      • 1...Bxe4
        • 2.Qa4#
      • 1...Sxc4
        • 2.Qxd7#
      • 1...Sxb8
        • 2.Rxc5#
      • 1...Bd5
        • 2.Qa4#
      • 1...Bc6
        • 2.Qa4#
      • 1...Ba8
        • 2.Qa4#
      • 1...Bc8
        • 2.Qa4#
      • 1...Sa4
        • 2.Qxa4#
      • 1...Sd5
        • 2.Qa4#
      • 1...Sa8
        • 2.Qa4#
      • 1...Sc8
        • 2.Qa4#
      • 1...Se5
        • 2.Rxc5#
      • 1...Sf6
        • 2.Rxc5#
      • 1...Sf8
        • 2.Rxc5#

FEATURES

  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 2
    • ADDED MATES = 14
    • REMOVED MATES = 0
  • Sets
    • S(d);N_GUARD,P_SPINB(e)::QAB(A),XS(f)
  • Tries
    • Try
      • R(I);P_PINS(d),XB(e)
      • Threat
        • QAB(A),XS(f)
      • Vars
        • S(f);N_GUARD::R1(I),XS(d)
      • Refutation
        • K(a);N_SPINS(d),S_FLIGHT
  • Actual
    • R(D);
    • Vars
      • K(a);OGATEB,S_FLIGHT,XR(D)::QAB1(A)
      • K(a);P-FLIGHT,P_SPINS(d),XP(F)::QAR1(A)
      • K(a);P_SPINP(b),S_FLIGHT::S(G)
      • B(e);P_SPINS(d),XP(E)::QAB1(A)
      • S(d);N_GUARD,P_SPINB(e),SBLOCK,XR(D)::QAB(A),XS(f)
      • S(f);N_GUARD,XR(I)::R1(D),XP(b)
      • B(e);P_SPINS(d)::QAB1(A)
      • B(e);P_SPINS(d),SBLOCK::QAB1(A)
      • S(d);N_GUARD,P_SPINB(e)::QAB1(A),XS(d)
      • S(d);N_GUARD,P_SPINB(e)::QAB1(A)
      • S(f);N_GUARD::R1(D),XP(b)
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