MESON Chess Problem Database

Problem Display
PID: 201042 (6KB/1p6/b1p1N1p1/2Pk4/2p3Q1/b1n5/3Nrp2/8 w - - 0 1)

Sprague, Gordon

The Observer, 1949

(First published on Sun Jul 3 1949)

6KB/1p6/b1p1N1p1/2Pk4/2p3Q1/b1n5/3Nrp2/8

#2

6 + 10

15239 Valois Notebooks 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Rxe6
      • 2.Qd4#
    • 1...Sb5
      • 2.Qxc4#
  • Tries
    • 1.Qxe2?
      • threat
        • 2.Qe5#
      • 1...Se4
        • 2.Qxe4#
      • 1...Sxe2!
    • 1.Qf5+?
      • 1...Re5
        • 2.Qxe5#
      • 1...gxf5!
    • 1.Qg5+?
      • 1...Re5
        • 2.Qxe5#
      • 1...Kxe6!
  • Keys
    • 1.Qf4!
      • threat
        • 2.Qd6#
      • 1...Kxe6
        • 2.Qf7#
      • 1...Rxd2
        • 2.Qe5#
      • 1...Rxe6
        • 2.Qd4#
      • 1...Bxc5
        • 2.Sc7#
      • 1...Re5
        • 2.Qxe5#
      • 1...Se4
        • 2.Qe5#
      • 1...Sb5
        • 2.Qxc4#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 5
    • REMOVED MATES = 0
  • Sets
    • R(a);SBLOCK,XS(D)::QAR1(B)
    • S(d);S_CUTB(g)::QAB1(B),XP(e)
  • Tries
    • Try
      • Q(B);XR(a)
      • Threat
        • QAR1(B)
      • Vars
        • S(d);N_GUARD::QAB1(B),XS(d)
      • Refutation
        • S(d);XQ(B)
    • Try
      • Q(B);CHECK
      • Vars
        • R(a);N_GUARD,P_SPINR(a)::QAR1(B),XR(a)
      • Refutation
        • P(i);XQ(B)
    • Try
      • Q(B);CHECK
      • Vars
        • R(a);N_GUARD,P_SPINR(a)::QAR1(B),XR(a)
      • Refutation
        • K(f);S_FLIGHT,XS(D)
  • Actual
    • Q(B);
    • Threat
      • QAR1(B)
    • Vars
      • K(f);OGATEB,S_FLIGHT,XS(D)::QAB1(B)
      • R(a);N_GUARD,XS(A)::QAR1(B)
      • R(a);SBLOCK,XS(D)::QAR1(B)
      • B(c);SBLOCK,XP(C)::S(D)
      • R(a);N_GUARD::QAR1(B),XR(a)
      • S(d);S_CUTR(a)::QAR1(B)
      • S(d);S_CUTB(g)::QAB1(B),XP(e)
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