MESON Chess Problem Database

Problem Display
PID: 33172 (6B1/2Qp4/1p4p1/qp4p1/1b2k1K1/1r6/2N1P3/2B2N2 w - - 0 1)

Wallis, Walter Warren

The Observer, 1961

6B1/2Qp4/1p4p1/qp4p1/1b2k1K1/1r6/2N1P3/2B2N2

#2

7 + 9

136 Problem Observer 2001

SOLUTION

  • SOUND
  • Sets
    • 1...Rb1
      • 2.Sg3#
    • 1...Rb2
      • 2.Sg3#
    • 1...Rc3
      • 2.Sd2#
    • 1...Rg3+
      • 2.Sxg3#
    • 1...Bc3
      • 2.Sg3#
    • 1...d6
      • 2.Qe7#
  • Tries
    • 1.Bf4?
      • threat
        • 2.Qe5#
      • 1...Rg3+
        • 2.Sxg3#
      • 1...gxf4
        • 2.Qxf4#
      • 1...Bc3
        • 2.Sg3#
      • 1...Bd6
        • 2.Qb7#
      • 1...d6
        • 2.Qe7#
      • 1...Qa1!
    • 1.Qd6?
      • threat
        • 2.Bd5#
        • 2.Qd4#
        • 2.Qd5#
      • 1...Rg3+
        • 2.Sxg3#
      • 1...Qa1
        • 2.Bd5#
        • 2.Qd5#
      • 1...Qa8
        • 2.Qd4#
      • 1...Rd3
        • 2.exd3#
      • 1...Bc3
        • 2.Sg3#
        • 2.Bd5#
        • 2.Qd5#
      • 1...Bc5
        • 2.Bd5#
        • 2.Qd5#
      • 1...Bxd6!
    • 1.Qc4+?
      • 1...Ke5
        • 2.Qd4#
      • 1...bxc4!
    • 1.Qb7+?
      • 1...d5
        • 2.Qxd5#
      • 1...Ke5!
  • Keys
    • 1.Bb2!
      • threat
        • 2.Qe5#
      • 1...Rg3+
        • 2.Sxg3#
      • 1...Rxb2
        • 2.Sg3#
      • 1...Rc3
        • 2.Sd2#
      • 1...Bc3
        • 2.Sg3#
      • 1...Bd6
        • 2.Qb7#
      • 1...d6
        • 2.Qe7#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 1
    • REMOVED MATES = 1
  • Sets
    • R(a);N_GUARD::S(B)
    • R(a);S_CUTB(b)::S(B)
    • R(a);CHECK,N_GUARD::S(B),XR(a)
    • B(b);S_CUTR(a)::S(B)
    • P(i);OGATE::QAR(F)
  • Tries
    • Try
      • B(A);
      • Threat
        • QAR1(F)
      • Vars
        • R(a);CHECK,N_GUARD::S(B),XR(a)
        • P(f);OGATE,XB(A)::QAR1(F),XP(f)
        • B(b);S_CUTR(a)::S(B)
        • B(b);S_CUTP(i)::QAB(F)
        • P(i);OGATE::QAR(F)
      • Refutation
        • Q(d);
    • Try
      • Q(F);
      • Threat
        • DUALS(3)
      • Vars
        • R(a);CHECK,N_GUARD::S(B),XR(a)
        • Q(d);::QAR1(F)
        • R(a);OGATE::P(D),XR(a)
      • Refutation
        • B(b);XQ(F)
    • Try
      • Q(F);CHECK
      • Vars
        • K(c);P-FLIGHT::QAB1(F)
      • Refutation
        • P(e);XQ(F)
    • Try
      • Q(F);CHECK
      • Vars
        • P(i);P_SPINP(i)::QAB1(F),XP(i)
      • Refutation
        • K(c);P-FLIGHT
  • Actual
    • B(A);
    • Threat
      • QAR1(F)
    • Vars
      • R(a);CHECK,N_GUARD::S(B),XR(a)
      • R(a);N_GUARD,XB(A)::S(B)
      • R(a);S_CUTB(b)::S(B)
      • B(b);S_CUTR(a)::S(B)
      • B(b);S_CUTP(i)::QAB(F)
      • P(i);OGATE::QAR(F)
HTML5 logo

Developed and maintained by Brian Stephenson.
Implemented with HTML5, MySQL, Perl (with, inter alia, CGI::Simple, HTML::Template & XML::LibXML) & CSS/Javascript (jQuery, Bootstrap & DataTables).