MESON Chess Problem Database

Problem Display
PID: 195802 (B1n2N2/R1pp4/1p1k4/1b5R/4Q3/6NK/2prp3/b7 w - - 0 1)

Sher, H

The Observer, 1942

(First published on Sun Feb 1 1942)

B1n2N2/R1pp4/1p1k4/1b5R/4Q3/6NK/2prp3/b7

#2

7 + 10

15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Rd4
      • 2.Qe5#
    • 1...Rd5
      • 2.Rxd5#
    • 1...Bd4
      • 2.Rd5#
    • 1...Be5
      • 2.Qxe5#
    • 1...Bd3
      • 2.Rd5#
    • 1...Bc6
      • 2.Qb4#
    • 1...c5
      • 2.Sf5#
    • 1...c6
      • 2.Rxd7#
  • Tries
    • 1.Qg6+?
      • 1...Bf6
        • 2.Qxf6#
      • 1...Ke7!
    • 1.Qf4+?
      • 1...Be5
        • 2.Qxe5#
      • 1...Ke7!
    • 1.Qe7+?
      • 1...Sxe7
        • 2.Se4#
      • 1...Kxe7!
  • Keys
    • 1.Qe3!
      • threat
        • 2.Sf5#
      • 1...Rd4
        • 2.Qe5#
      • 1...Rd5
        • 2.Rxd5#
      • 1...Bd4
        • 2.Rd5#
      • 1...Bd3
        • 2.Rd5#
      • 1...Bc6
        • 2.Qa3#
      • 1...Se7
        • 2.Se4#
      • 1...c6
        • 2.Rxd7#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 1
    • REMOVED MATES = 2
  • Sets
    • R(c);S_CUTB(a)::QAB1(C)
    • R(c);N_GUARD::R1(D),XR(c)
    • B(a);S_CUTR(c)::R1(D)
    • B(a);N_GUARD::QAB1(C),XB(a)
    • B(e);S_CUTR(c)::R1(D)
    • B(e);S_CUTP(h)::QAB(C)
    • P(h);SBLOCK::S(A)
    • P(h);OGATE::R1(E),XP(i)
  • Tries
    • Try
      • Q(C);CHECK
      • Vars
        • B(a);N_GUARD,P_SPINB(a)::QAR2(C),XB(a)
      • Refutation
        • K(g);S_FLIGHT
    • Try
      • Q(C);CHECK
      • Vars
        • B(a);N_GUARD,P_SPINB(a)::QAB1(C),XB(a)
      • Refutation
        • K(g);S_FLIGHT
    • Try
      • Q(C);CHECK
      • Vars
        • S(j);SBLOCK,XQ(C)::S(A)
      • Refutation
        • K(g);S_FLIGHT,XQ(C)
  • Actual
    • Q(C);
    • Threat
      • S(A)
    • Vars
      • R(c);S_CUTB(a)::QAB1(C)
      • R(c);N_GUARD::R1(D),XR(c)
      • B(a);S_CUTR(c)::R1(D)
      • B(e);S_CUTR(c)::R1(D)
      • B(e);S_CUTP(h)::QAB(C)
      • S(j);SBLOCK::S(A)
      • P(h);OGATE::R1(E),XP(i)
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