MESON Chess Problem Database

Problem Display
PID: 144755 (8/1B1p1K2/8/4kNp1/1P1Np1R1/3pqp1p/1Q6/2n5 w - - 0 1)

Sprague, Gordon

Chess, 1954

8/1B1p1K2/8/4kNp1/1P1Np1R1/3pqp1p/1Q6/2n5

#2

7 + 9

SOLUTION

  • SOUND
  • Sets
    • 1...Qg1
      • 2.Rxe4#
    • 1...Qd2
      • 2.Rxe4#
    • 1...Qf2
      • 2.Rxe4#
  • Tries
    • 1.Sc2+?
      • 1...Kxf5
        • 2.Sxe3#
      • 1...Qd4!
    • 1.Sc6+?
      • 1...Kd5
        • 2.Sa5#
        • 2.Se5#
      • 1...Kxf5!
    • 1.Sxe3?
      • threat
        • 2.Sc4#
        • 2.Sb5#
        • 2.Sdf5#
      • 1...Kd6
        • 2.Sb5#
        • 2.Qh2#
      • 1...Sa2
        • 2.Sc4#
      • 1...Se2
        • 2.Sc4#
      • 1...Sb3
        • 2.Sc4#
      • 1...d5!
  • Keys
    • 1.Sd6!
      • threat
        • 2.Sc4#
      • 1...Qf4+
        • 2.S4f5#
      • 1...Kxd6
        • 2.Sb5#
      • 1...Qxd4
        • 2.Qh2#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 3
    • REMOVED MATES = 3
  • Sets
    • Q(c);N_GUARD::R1(D),XP(f)
  • Tries
    • Try
      • S(C);CHECK
      • Vars
        • K(g);P-FLIGHT,XS(E)::S(C),XQ(c)
      • Refutation
        • Q(c);P_SPINQ(c)
    • Try
      • S(C);CHECK
      • Refutation
        • K(g);P-FLIGHT,XS(E)
    • Try
      • S(E);XQ(c)
      • Threat
        • DUALS(3)
      • Vars
        • S(a);::S(E)
      • Refutation
        • P(i);
  • Actual
    • S(E);
    • Threat
      • S(E)
    • Vars
      • Q(c);CHECK,N_GUARD::QAB(A)+S(C)
      • K(g);S_FLIGHT,XS(E)::S(C)
      • Q(c);N_GUARD,P_SPINQ(c),SBLOCK,XS(C)::QAB(A)
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