MESON Chess Problem Database

Problem Display
PID: 466 (8/4K3/7B/4kb2/3p4/1Q6/2n1Pn2/1BNRr3 w - - 0 1)

Leaver, Rev DC

The Observer, 1956

8/4K3/7B/4kb2/3p4/1Q6/2n1Pn2/1BNRr3

#2

7 + 6

SOLUTION

  • SOUND
  • Sets
    • 1...Bd3
      • 2.Qe6#
    • 1...Be4
      • 2.Qe6#
    • 1...Be6
      • 2.Qxe6#
    • 1...Bg6
      • 2.Qe6#
    • 1...Bh7
      • 2.Qe6#
    • 1...Sa1
      • 2.Qb5#
    • 1...Se4
      • 2.Sd3#
  • Tries
    • 1.Sd3+?
      • 1...Ke4
        • 2.Qb7#
      • 1...Bxd3
        • 2.Qe6#
      • 1...Sxd3!
    • 1.Bf4+?
      • 1...Ke4
        • 2.Qf3#
      • 1...Kxf4!
    • 1.Bg7+?
      • 1...Ke4
        • 2.Rxd4#
        • 2.Qf3#
      • 1...Kf4!
  • Keys
    • 1.e4!
      • threat
        • 2.Qd5#
      • 1...Kxe4
        • 2.Rxe1#
      • 1...Rxe4
        • 2.Qb5#
      • 1...Bxe4
        • 2.Qe6#
      • 1...Sxe4
        • 2.Sd3#
      • 1...Be6
        • 2.Qxe6#
      • 1...Se3
        • 2.Qb8#
      • 1...Sb4
        • 2.Qg3#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 4
    • REMOVED MATES = 4
  • Sets
    • B(f);N_GUARD::QAR1(E)
    • B(f);N_GUARD,SBLOCK::QAR1(E)
    • B(f);N_GUARD::QAR1(E),XB(f)
    • S(b);::QAR(E)
    • S(c);N_GUARD,SBLOCK,S_CUTB(f)::S(B)
  • Tries
    • Try
      • S(B);CHECK
      • Vars
        • K(e);P-FLIGHT::QAB(E)
        • B(f);XS(B)::QAR1(E)
      • Refutation
        • S(c);XS(B)
    • Try
      • B(F);CHECK
      • Vars
        • K(e);P-FLIGHT,P_SPINS(b)::QAB1(E)
      • Refutation
        • K(e);P_PINP(D),S_FLIGHT,XB(F)
    • Try
      • B(F);CHECK
      • Refutation
        • K(e);P_PINP(D),S_FLIGHT
  • Actual
    • P(D);
    • Threat
      • QAR1(E)
    • Vars
      • K(e);OGATEB,P-FLIGHT,P_SPINS(b),XP(D)::R(C),XR(a)
      • R(a);SBLOCK,XP(D)::QAR(E)
      • B(f);N_GUARD,SBLOCK,XP(D)::QAR1(E)
      • S(c);N_GUARD,SBLOCK,XP(D)::S(B)
      • B(f);N_GUARD::QAR1(E),XB(f)
      • S(b);::QAB(E)
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