MESON Chess Problem Database

Problem Display
PID: 102113 (8/1R6/7K/R2N2Qp/2k4r/p1P5/2nrP1n1/2b1BB2 w - - 0 1)

Andrade, Barry Jack da Costa

1st HM., The Observer, 1958

(First published on Sun Apr 13 1958)

8/1R6/7K/R2N2Qp/2k4r/p1P5/2nrP1n1/2b1BB2

#2

9 + 8

6490 yacpdb 2009

SOLUTION

  • SOUND
  • Sets
    • 1...Rxe2
      • 2.Bxe2#
    • 1...Rd3
      • 2.exd3#
    • 1...Sa1
      • 2.Rb4#
    • 1...Scxe1
      • 2.Rb4#
    • 1...Sce3
      • 2.Rb4#
    • 1...Sb4
      • 2.Rxb4#
    • 1...Sd4
      • 2.Rb4#
  • Tries
    • 1.Se3+?
      • 1...Scxe3
        • 2.Rc5#
        • 2.Qc5#
      • 1...Sgxe3
        • 2.Rc5#
        • 2.Qc5#
      • 1...Kxc3!
    • 1.e3+?
      • 1...Re2
        • 2.Bxe2#
      • 1...Rd3!
    • 1.e4+?
      • 1...Re2
        • 2.Bxe2#
      • 1...Rd3!
  • Keys
    • 1.Qg8!
      • threat
        • 2.Qc8#
      • 1...Rd1+
        • 2.Se3#
      • 1...Rxe2+
        • 2.Sf4#
      • 1...Rd3+
        • 2.Se3#
      • 1...Rdd4+
        • 2.Se3#
      • 1...Rxd5+
        • 2.e3#
      • 1...Sb4
        • 2.Rxb4#
      • 1...Sd4
        • 2.Rb4#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 2
    • ADDED MATES = 3
    • REMOVED MATES = 3
  • Sets
    • R(c);OGATE,P_PINQ(G),P_SPINR(c),XP(C)::B(B),XR(c)
    • R(c);OGATE,P_PINQ(G)::P(C),XR(c)
    • S(b);N_GUARD::R1(I)
    • S(b);N_GUARD,XB(A)::R1(I)
    • S(b);N_GUARD::R1(I),XS(b)
  • Tries
    • Try
      • S(F);CHECK
      • Refutation
        • K(f);P-FLIGHT,P_SPINR(c),XP(D)
    • Try
      • P(C);CHECK
      • Vars
        • R(c);N_GUARD,P_SPINR(c)::B(B),XR(c)
      • Refutation
        • R(c);P_SPINR(c)
    • Try
      • P(C);CHECK
      • Vars
        • R(c);N_GUARD,P_PINQ(G),P_SPINR(c)::B(B),XR(c)
      • Refutation
        • R(c);P_PINQ(G),P_SPINR(c)
  • Actual
    • Q(G);
    • Threat
      • QAR(G)
    • Vars
      • R(c);CHECK::QAB(G)+S(F),DCHECK
      • R(c);CHECK,N_GUARD,P_SPINR(c),XP(C)::QAB(G)+S(F)
      • R(c);CHECK,N_GUARD,P_SPINR(c),XS(F)::B(B)+P(C)
      • S(b);N_GUARD::R1(I),XS(b)
      • S(b);N_GUARD::R1(I)
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