MESON Chess Problem Database

Problem Display
PID: 194407 (1q4BB/1r3r2/N2n4/R1P3b1/1pk1p1p1/3RnNP1/4PK2/1Q1b4 w - - 0 1)

Wallis, Walter Warren

The Observer, 1940

(First published on Sun Jun 2 1940)

1q4BB/1r3r2/N2n4/R1P3b1/1pk1p1p1/3RnNP1/4PK2/1Q1b4

#2

11 + 11

15239 Valois Notebooks 2019

SOLUTION

  • SOUND
  • Sets
    • 1...Bxe2
      • 2.Qb3#
    • 1...Bb3
      • 2.Qxb3#
    • 1...Bf4
      • 2.Sd2#
    • 1...Bf6
      • 2.Sd2#
    • 1...Sc2
      • 2.Qb3#
    • 1...Sef5
      • 2.Se5#
    • 1...Sb5
      • 2.Qxb4#
    • 1...Sdf5
      • 2.Sd2#
    • 1...exd3
      • 2.Qxd3#
  • Tries
    • 1.Bxf7+?
      • 1...Sd5
        • 2.Se5#
        • 2.Bxd5#
      • 1...Sxf7
        • 2.Sd2#
      • 1...Rxf7!
    • 1.Qa2+?
      • 1...Bb3
        • 2.Qxb3#
      • 1...b3!
    • 1.Qxd1?
      • threat
        • 2.Qb3#
      • 1...exd3
        • 2.Qxd3#
      • 1...Sc2
        • 2.Qxc2#
      • 1...b3
        • 2.Rc3#
      • 1...Sxd1+!
    • 1.Qb2?
      • threat
        • 2.Rd4#
        • 2.Qd4#
      • 1...Sc2
        • 2.Qb3#
      • 1...Bf6
        • 2.Sd2#
      • 1...Sef5
        • 2.Se5#
      • 1...Sb5
        • 2.Qxb4#
      • 1...Sdf5
        • 2.Sd2#
      • 1...exd3!
  • Keys
    • 1.Ba1!
      • threat
        • 2.Rd4#
      • 1...exd3
        • 2.Qxd3#
      • 1...Bf6
        • 2.Sd2#
      • 1...Sc2
        • 2.Qb3#
      • 1...Sef5
        • 2.Se5#
      • 1...Sb5
        • 2.Qxb4#
      • 1...Sdf5
        • 2.Sd2#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 0
    • REMOVED MATES = 3
  • Sets
    • B(a);N_GUARD,XP(B)::QAB1(A)
    • B(a);N_GUARD::QAB1(A),XB(a)
    • B(g);N_PINS(E)::S(E)
    • S(b);S_CUTB(a)::QAB1(A)
    • S(b);N_PINS(E)::S(E)
    • S(h);S_CUTR(i)::QAR1(A),XP(c)
    • S(h);N_PINS(E)::S(E)
    • P(e);OGATE,XR(D)::QAB1(A),XP(e)
  • Tries
    • Try
      • B(J);CHECK,N_SPINS(E),XR(j)
      • Vars
        • S(h);XB(J)::S(E)
      • Refutation
        • R(i);P_PINS(E),XB(J)
    • Try
      • Q(A);CHECK
      • Vars
        • B(a);N_GUARD,P_SPINB(a)::QAB1(A),XB(a)
      • Refutation
        • P(c);P_SPINP(c)
    • Try
      • Q(A);XB(a)
      • Threat
        • QAB1(A)
      • Vars
        • P(e);OGATE,XR(D)::QAB1(A),XP(e)
        • S(b);N_GUARD::QAR2(A),XS(b)
        • P(c);N_GUARD::R1(D)
      • Refutation
        • S(b);CHECK,XQ(A)
    • Try
      • Q(A);
      • Threat
        • DUALS(2)
      • Vars
        • S(b);S_CUTB(a)::QAB1(A)
        • B(g);N_PINS(E)::S(E)
        • S(b);N_PINS(E)::S(E)
        • S(h);S_CUTR(i)::QAR1(A),XP(c)
        • S(h);N_PINS(E)::S(E)
      • Refutation
        • P(e);XR(D)
  • Actual
    • B(K);
    • Threat
      • R1(D)
    • Vars
      • P(e);OGATE,XR(D)::QAB1(A),XP(e)
      • B(g);N_PINS(E)::S(E)
      • S(b);S_CUTB(a)::QAB1(A)
      • S(b);N_PINS(E)::S(E)
      • S(h);S_CUTR(i)::QAR1(A),XP(c)
      • S(h);N_PINS(E)::S(E)
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).