MESON Chess Problem Database

Problem Display
PID: 154477 (8/8/B4Qp1/3N2p1/2qN4/3k4/n3R1K1/1b4n1 w - - 0 1)

McWilliam, Robert C

US Problem Bulletin, 1987

8/8/B4Qp1/3N2p1/2qN4/3k4/n3R1K1/1b4n1

#2

6 + 7

15393 McWilliam Scrapbook 2015
3713 Snap 2015

SOLUTION

  • SOUND
  • Sets
    • 1...Qb5
      • 2.Bxb5#
    • 1...Sc3
      • 2.Sb4#
  • Tries
    • 1.Rd2+?
      • 1...Ke4
        • 2.Qe6#
      • 1...Kxd2!
    • 1.Qe5?
      • threat
        • 2.Qe3#
        • 2.Qe4#
      • 1...Sxe2
        • 2.Qe3#
      • 1...Qb5
        • 2.Bxb5#
      • 1...Sc3
        • 2.Sb4#
        • 2.Qe3#
      • 1...Qxa6!
    • 1.Qf2?
      • threat
        • 2.Qe3#
      • 1...Qb5
        • 2.Bxb5#
      • 1...Qxa6!
  • Keys
    • 1.Sb3!
      • 1...Kxe2
        • 2.Qf1#
      • 1...Qxa6
        • 2.Qxa6#
      • 1...Sxe2
        • 2.Qxg6#
      • 1...Qb5
        • 2.Bxb5#
      • 1...Bc2
        • 2.Re3#
      • 1...Sf3
        • 2.Qxf3#
      • 1...Sh3
        • 2.Qf3#
      • 1...Sc1
        • 2.Sxc1#
      • 1...Sc3
        • 2.Sc1#
      • 1...Sb4
        • 2.Sc1#
      • 1...g4
        • 2.Sf4#

Anticipated by 1099(1873)

FEATURES

  • Static
    • TYPE = INCOMPLETE_BLOCK
    • CHANGED MATES = 1
    • ADDED MATES = 9
    • REMOVED MATES = 0
  • Sets
    • Q(e);OGATEB::B(E),XQ(e)
    • S(c);N_GUARD,SBLOCK::S(D)
  • Tries
    • Try
      • R(A);CHECK
      • Vars
        • K(d);N_SPINQ(e),S_FLIGHT::QAR2(F)
      • Refutation
        • K(d);N_SPINQ(e),P-FLIGHT,XR(A)
    • Try
      • Q(F);
      • Threat
        • DUALS(2)
      • Vars
        • S(b);XR(A)::QAR1(F)
        • Q(e);OGATEB::B(E),XQ(e)
      • Refutation
        • Q(e);N_SPINQ(e),XB(E)
    • Try
      • Q(F);
      • Threat
        • QAR1(F)
      • Vars
        • Q(e);OGATEB::B(E),XQ(e)
      • Refutation
        • Q(e);N_SPINQ(e),XB(E)
  • Actual
    • S(C);
    • Vars
      • K(d);OGATEB,S_FLIGHT,XR(A)::QAB1(F)
      • Q(e);N_SPINQ(e),OGATE,XB(E)::QAB(F),XQ(e)
      • S(b);SBLOCK,XR(A)::QAB(F),XP(g)
      • Q(e);OGATEB::B(E),XQ(e)
      • B(a);SBLOCK::R1(A)
      • S(b);N_GUARD::QAR2(F),XS(b)
      • S(b);N_GUARD::QAR2(F)
      • S(c);N_GUARD::S(C),XS(c)
      • S(c);N_GUARD::S(C)
      • P(f);N_GUARD::S(D)
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