MESON Chess Problem Database

Problem Display
PID: 587 (K3R3/pp2B3/q6r/1NpPNRP1/4k1P1/4n3/Bn2Qp2/4br1b w - - 0 1)

Valois, Paul Stedman

The Observer, 1966

K3R3/pp2B3/q6r/1NpPNRP1/4k1P1/4n3/Bn2Qp2/4br1b

#2

11 + 12

136 Problem Observer 2014

SOLUTION

  • SOUND
  • Sets
    • 1...Bf3
      • 2.Qxf3#
    • 1...Sd1
      • 2.Qd3#
    • 1...Sd3
      • 2.Qxd3#
    • 1...Sa4
      • 2.Qd3#
    • 1...Sc4
      • 2.Qd3#
  • Tries
    • 1.Bb1+?
      • 1...Sd3
        • 2.Qxd3#
      • 1...Kxd5!
    • 1.Bxc5?
      • threat
        • 2.Qxe3#
      • 1...Qxa2
        • 2.Sg6#
      • 1...Sc4
        • 2.Qd3#
      • 1...Qa3
        • 2.Sg6#
      • 1...Rh3
        • 2.Sc6#
      • 1...Sd1
        • 2.Qd3#
      • 1...Bd2!
    • 1.Rf4+?
      • 1...Kxe5
        • 2.Bd6#
      • 1...Kxf4!
    • 1.Qc2+?
      • 1...Sd3
        • 2.Qxd3#
      • 1...Sxc2!
  • Keys
    • 1.Sc4!
      • threat
        • 2.Qxe3#
      • 1...Sxc4
        • 2.Bb1#
      • 1...Qa3
        • 2.Bf6#
      • 1...Rh3
        • 2.Bd6#
      • 1...Bd2
        • 2.Sxd2#
      • 1...Sd1
        • 2.Bb1#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 2
    • ADDED MATES = 3
    • REMOVED MATES = 3
  • Sets
    • B(c);N_GUARD::QAB1(B),XB(c)
    • S(d);N_GUARD::QAB1(B)
    • S(d);N_GUARD::QAB1(B),XS(d)
  • Tries
    • Try
      • B(A);CHECK
      • Vars
        • S(d);N_GUARD,N_SPINS(f),P_SPINS(d)::QAB1(B),XS(d)
      • Refutation
        • K(g);N_SPINS(f),S_FLIGHT,XP(E)
    • Try
      • B(I);XP(h)
      • Threat
        • QAR1(B),XS(f)
      • Vars
        • Q(i);N_GUARD,XB(A)::R(K)+S(F)
        • S(d);N_GUARD::QAB1(B)
        • Q(i);N_GUARD::R(K)+S(F)
        • R(j);N_GUARD::R(K)+S(F)
      • Refutation
        • B(a);
    • Try
      • R(G);CHECK
      • Vars
        • K(g);P-FLIGHT,XS(F)::R(K)+B(I),DCHECK
      • Refutation
        • K(g);N_SPINS(f),P-FLIGHT,XR(G)
    • Try
      • Q(B);CHECK,N_PINS(f)
      • Vars
        • S(d);N_GUARD,P_SPINS(d)::QAB1(B),XS(d)
      • Refutation
        • S(f);XQ(B)
  • Actual
    • S(F);
    • Threat
      • QAR1(B),XS(f)
    • Vars
      • S(d);N_GUARD,XS(F)::B(A)
      • Q(i);N_GUARD::R(K)+B(I)
      • R(j);N_GUARD::R(K)+B(I)
      • B(a);N_GUARD::S(F),XB(a)
      • S(d);N_GUARD::B(A)
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