MESON Chess Problem Database

Problem Display
PID: 194796 (8/qr6/n2P3R/1nkN4/p1rN4/2pP4/6B1/1RQ3BK w - - 0 1)

Sher, H

The Observer, 1941

(First published on Sun Jun 29 1941)

8/qr6/n2P3R/1nkN4/p1rN4/2pP4/6B1/1RQ3BK

#2

10 + 8

15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Rc7
      • 2.Rxb5#
    • 1...Rd7
      • 2.Rxb5#
    • 1...Re7
      • 2.Rxb5#
    • 1...Rf7
      • 2.Rxb5#
    • 1...Rg7
      • 2.Rxb5#
    • 1...Rh7
      • 2.Rxb5#
  • Tries
    • 1.Sxb5+?
      • 1...Rd4
        • 2.Qxc3#
      • 1...Kc6!
  • Keys
    • 1.Sb6!
      • threat
        • 2.Rxb5#
      • 1...Kxb6
        • 2.Rxb5#
      • 1...Qxb6
        • 2.Qg5#
      • 1...Rxd4
        • 2.Sxa4#
      • 1...Rxb6
        • 2.Qg5#
      • 1...Sxd4
        • 2.Qg5#
      • 1...Sxd6
        • 2.Se6#
      • 1...Rb4
        • 2.Sb3#
      • 1...Sa3
        • 2.Qg5#
      • 1...Sbc7
        • 2.Sd7#
      • 1...Sb4
        • 2.Sb3#
      • 1...Sac7
        • 2.Sd7#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 11
    • REMOVED MATES = 6
  • Sets
    • R(h);N_GUARD::R1(A),XS(d)
    • R(h);N_GUARD,P_PINR(J)::R1(A),XS(d)
  • Tries
    • Try
      • S(G);CHECK,XS(d)
      • Vars
        • R(c);P_SPINP(a),P_SPINR(c)::QAR2(B),XP(a)
      • Refutation
        • K(e);P-FLIGHT
  • Actual
    • S(H);
    • Threat
      • R1(A),XS(d)
    • Vars
      • K(e);P_SPINS(d),S_FLIGHT,XS(H)::R1(A),XS(d)
      • Q(g);SBLOCK,XS(H)::QAR(B)
      • R(c);N_GUARD,P_SPINP(a),P_SPINR(c),XS(G)::S(H),XP(b)
      • R(h);SBLOCK,XS(H)::QAR(B)
      • S(d);P_SPINS(d),XS(G)::QAR(B)
      • S(d);SBLOCK,XP(I)::B(C)+S(G),DCHECK
      • R(c);P_SPINP(a),SBLOCK::B(C)+S(G),DCHECK
      • S(d);::QAR(B)
      • S(d);S_CUTR(h)::S(H)
      • S(f);SBLOCK::B(C)+S(G),DCHECK
      • S(f);S_CUTR(h)::S(H)
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