MESON Chess Problem Database

Problem Display
PID: 194722 (KnN1R1b1/5p2/6p1/1B1k2r1/N1p1n3/5ppQ/1Brp4/6b1 w - - 0 1)

Easom, GWA

The Observer, 1941

(First published on Sun Apr 20 1941)

KnN1R1b1/5p2/6p1/1B1k2r1/N1p1n3/5ppQ/1Brp4/6b1

#2

7 + 13

15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Rg4
      • 2.Re5#
    • 1...Re5
      • 2.Rxe5#
    • 1...Sc5
      • 2.Sab6#
    • 1...f5
      • 2.Re5#
  • Tries
    • 1.Qf5+?
      • 1...gxf5
        • 2.Re5#
      • 1...Rxf5!
    • 1.Qd7+?
      • 1...Sd6
        • 2.Qxd6#
      • 1...Sxd7!
    • 1.Qh4?
      • threat
        • 2.Qxe4#
      • 1...Rg4
        • 2.Re5#
      • 1...Re5
        • 2.Rxe5#
      • 1...Sf2
        • 2.Qd4#
      • 1...Sc3
        • 2.Qxc4#
      • 1...Sc5
        • 2.Sab6#
      • 1...Sf6
        • 2.Qxg5#
      • 1...f5
        • 2.Re5#
      • 1...Sd6!
  • Keys
    • 1.Qg4!
      • threat
        • 2.Qxe4#
      • 1...Rxg4
        • 2.Re5#
      • 1...Re5
        • 2.Rxe5#
      • 1...Sf2
        • 2.Qd4#
      • 1...Sc3
        • 2.Qxc4#
      • 1...Sc5
        • 2.Sab6#
      • 1...Sd6
        • 2.Se7#
      • 1...Sf6
        • 2.Qxg5#
      • 1...f5
        • 2.Re5#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 4
    • REMOVED MATES = 0
  • Sets
    • R(i);N_GUARD::R1(G)
    • R(i);N_GUARD::R1(G),XR(i)
    • S(g);SBLOCK,S_CUTB(a)::S(C)
    • P(k);S_CUTR(i)::R1(G)
  • Tries
    • Try
      • Q(B);CHECK
      • Vars
        • P(j);XQ(B)::R1(G)
      • Refutation
        • R(i);XQ(B)
    • Try
      • Q(B);CHECK
      • Vars
        • S(g);N_GUARD,P_SPINS(g)::QAR1(B),XS(g)
      • Refutation
        • S(l);XQ(B)
    • Try
      • Q(B);
      • Threat
        • QAB1(B),XS(g)
      • Vars
        • R(i);N_GUARD::R1(G)
        • R(i);N_GUARD::R1(G),XR(i)
        • S(g);OGATE::QAR1(B)
        • S(g);OGATE::QAB1(B),XP(f)
        • S(g);SBLOCK,S_CUTB(a)::S(C)
        • S(g);N_GUARD,S_CUTP(k)::QAR(B),XR(i)
        • P(k);S_CUTR(i)::R1(G)
      • Refutation
        • S(g);
  • Actual
    • Q(B);
    • Threat
      • QAB1(B),XS(g)
    • Vars
      • R(i);N_GUARD,XQ(B)::R1(G)
      • R(i);N_GUARD::R1(G),XR(i)
      • S(g);OGATE::QAR1(B)
      • S(g);OGATE::QAB1(B),XP(f)
      • S(g);SBLOCK,S_CUTB(a)::S(C)
      • S(g);SBLOCK::S(F)
      • S(g);N_GUARD,S_CUTP(k)::QAR(B),XR(i)
      • P(k);S_CUTR(i)::R1(G)
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