MESON Chess Problem Database

Problem Display
PID: 198575 (5q2/pN3r2/4P3/2p2R1r/2P1n1Qb/K1PkN3/2p1Rpp1/B1n2B2 w - - 0 1)

Byas, Walter

The Observer, 1944

(First published on Sun Aug 6 1944)

5q2/pN3r2/4P3/2p2R1r/2P1n1Qb/K1PkN3/2p1Rpp1/B1n2B2

#2

11 + 12

15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Rh6
      • 2.Rd5#
    • 1...Rhh7
      • 2.Rd5#
    • 1...Rh8
      • 2.Rd5#
    • 1...Bg5
      • 2.Rd5#
    • 1...Sxe2
      • 2.Qxe2#
    • 1...Sg5
      • 2.Rd5#
    • 1...Sd6
      • 2.Sxc5#
  • Tries
    • 1.Sxc5+?
      • 1...Sxc5
        • 2.Qd4#
      • 1...Qxc5+!
    • 1.Rd2+?
      • 1...Kxe3
        • 2.Qf4#
      • 1...Kxd2!
  • Keys
    • 1.Sd1!
      • threat
        • 2.Qxe4#
      • 1...Kxc4
        • 2.Rxe4#
      • 1...Sxe2
        • 2.Qxe2#
      • 1...Sxc3
        • 2.Sb2#
      • 1...Sd2
        • 2.Re3#
      • 1...Sg3
        • 2.Sxf2#
      • 1...Sg5
        • 2.Rd5#
      • 1...Sd6
        • 2.Sxc5#
      • 1...Sf6
        • 2.Rf3#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 5
    • REMOVED MATES = 4
  • Sets
    • R(i);N_GUARD::R(I)
    • B(g);S_CUTR(i)::R(I)
    • S(a);OGATE,P_SPINS(a),XR(C)::QAB1(H),XS(a)
    • S(f);S_CUTR(i)::R(I)
    • S(f);N_GUARD,S_CUTQ(l)::S(K),XP(h)
  • Tries
    • Try
      • S(K);CHECK,P_SPINS(K),XP(h)
      • Vars
        • S(f);OGATE,XS(K)::QAR1(H)
      • Refutation
        • Q(l);CHECK,XS(K)
    • Try
      • R(C);CHECK
      • Vars
        • K(e);P-FLIGHT,XS(F)::QAB1(H)
      • Refutation
        • K(e);P-FLIGHT,XR(C)
  • Actual
    • S(F);
    • Threat
      • QAB1(H),XS(f)
    • Vars
      • K(e);P_SPINS(f),S_FLIGHT,XP(G)::B(B)+R(C),DCHECK,XS(f)
      • S(a);OGATE,P_SPINS(a),XR(C)::QAB1(H),XS(a)
      • S(f);SBLOCK,XP(E)::S(F)
      • S(f);SBLOCK::B(B)+R(C),DCHECK
      • S(f);N_GUARD,S_CUTB(g)::S(F),XP(c)
      • S(f);S_CUTR(i)::R(I)
      • S(f);N_GUARD,S_CUTQ(l)::S(K),XP(h)
      • S(f);S_CUTR(k)::R(I)
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