MESON Chess Problem Database

Problem Display
PID: 40783 (4B3/4P3/2pprp2/3b1Np1/N1k2bR1/2P1p2K/nRQ3p1/2n3B1 w - - 0 1)

Butcher, FG

The Observer, 1961

4B3/4P3/2pprp2/3b1Np1/N1k2bR1/2P1p2K/nRQ3p1/2n3B1

#2

10 + 12

136 Problem Observer 1972

SOLUTION

  • SOUND
  • Sets
    • 1...Re5
      • 2.Sxd6#
    • 1...Rxe7
      • 2.Sxd6#
    • 1...Se2
      • 2.Qxe2#
    • 1...Sb3
      • 2.Qe2#
    • 1...Sd3
      • 2.Qb3#
    • 1...Sxc3
      • 2.Qxc3#
    • 1...Sb4
      • 2.Rxb4#
    • 1...e2
      • 2.Sb6#
    • 1...c5
      • 2.Sb6#
      • 2.Bb5#
  • Tries
    • 1.Bxe3?
      • threat
        • 2.Sb6#
      • 1...Rxe3+
        • 2.Sxe3#
      • 1...Sb3
        • 2.Qe2#
      • 1...Sb4
        • 2.Rxb4#
      • 1...g1S+!
    • 1.Rxf4+?
      • 1...Re4
        • 2.Sxe3#
        • 2.Sxd6#
      • 1...Be4
        • 2.Sxe3#
      • 1...gxf4!
    • 1.Qd1?
      • threat
        • 2.Qd4#
      • 1...Sb3
        • 2.Qe2#
      • 1...Sb4
        • 2.Rxb4#
      • 1...Se2
        • 2.Qxe2#
      • 1...Sd3
        • 2.Qb3#
      • 1...c5
        • 2.Bb5#
      • 1...Re4!
  • Keys
    • 1.Bf7!
      • 1...Rxe7
        • 2.Sxd6#
      • 1...Sxc3
        • 2.Qxc3#
      • 1...Bf3
        • 2.Sxe3#
      • 1...Be4
        • 2.Qxe4#
      • 1...Sb3
        • 2.Qe2#
      • 1...Sb4
        • 2.Rxb4#
      • 1...Re4
        • 2.Qxe4#
      • 1...Re5
        • 2.Sxd6#
      • 1...Se2
        • 2.Qxe2#
      • 1...Sd3
        • 2.Qb3#
      • 1...e2
        • 2.Sb6#
      • 1...c5
        • 2.Sb6#

FEATURES

  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 0
    • ADDED MATES = 4
    • REMOVED MATES = 0
  • Sets
    • R(k);N_GUARD::S(H),XP(j)
    • R(k);N_GUARD,XP(I)::S(H),XP(j)
    • S(a);N_GUARD::QAB(C),XS(a)
    • S(a);N_GUARD::QAB(C)
    • S(a);N_GUARD,SBLOCK::QAB1(C)
    • S(b);OGATE,P_SPINS(b),XP(D)::QAR1(C),XS(b)
    • S(b);N_GUARD::R1(B),XS(b)
    • P(d);::S(F)
  • Tries
    • Try
      • B(A);XP(d)
      • Threat
        • S(F)
      • Vars
        • R(k);CHECK,XB(A)::S(H),XR(k)
        • S(a);N_GUARD::QAB(C)
        • S(b);N_GUARD::R1(B),XS(b)
      • Refutation
        • P(c);CHECK
    • Try
      • R(G);CHECK,XB(f)
      • Vars
        • B(g);P_SPINB(g)::S(H),XP(d)
      • Refutation
        • P(h);XR(G)
    • Try
      • Q(C);
      • Threat
        • QAR1(C)
      • Vars
        • S(a);N_GUARD::QAB(C)
        • S(b);N_GUARD::R1(B),XS(b)
        • S(a);N_GUARD::QAB(C),XS(a)
        • S(a);N_GUARD,SBLOCK::QAB1(C)
        • P(i);OGATE::B(J)
      • Refutation
        • R(k);N_SPINB(f)
  • Actual
    • B(J);
    • Vars
      • R(k);N_GUARD,XP(I)::S(H),XP(j)
      • S(b);OGATE,P_SPINS(b),XP(D)::QAR1(C),XS(b)
      • B(g);P_SPINR(k)::S(H),XP(d)
      • B(g);N_GUARD,N_SPINB(f),P_SPINR(k)::QAR2(C),XB(g)
      • S(a);N_GUARD::QAB(C)
      • S(b);N_GUARD::R1(B),XS(b)
      • R(k);N_GUARD,N_SPINB(f),P_SPINB(g)::QAR2(C),XR(k)
      • R(k);N_GUARD::S(H),XP(j)
      • S(a);N_GUARD::QAB(C),XS(a)
      • S(a);N_GUARD,SBLOCK::QAB1(C)
      • P(d);::S(F)
      • P(i);SBLOCK::S(F)
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