MESON Chess Problem Database

Problem Display
PID: 68294 (2r1rb2/p1Pk1P2/3ppP2/3N4/1n1Q2nK/3N4/B6B/2R1R3 w - - 0 1)

Sydenham, Colin Peter

2nd HM., Due Alfieri, 1980

2r1rb2/p1Pk1P2/3ppP2/3N4/1n1Q2nK/3N4/B6B/2R1R3

#2

11 + 9

56 The Problemist 2006
15513 Selected Chess Problems of Colin Sydenham 2015

SOLUTION

  • SOUND
  • Sets
    • 1...Sxa2
      • 2.Qa4#
    • 1...Sc2
      • 2.Qa4#
    • 1...Sxd3
      • 2.Qa4#
    • 1...Sxd5
      • 2.Qa4#
    • 1...Sa6
      • 2.Qa4#
    • 1...a5
      • 2.Sb6#
    • 1...a6
      • 2.Sb6#
  • Tries
    • 1.Se5+?
      • 1...dxe5
        • 2.Sb6#
      • 1...Sxe5!
  • Keys
    • 1.Se7!
      • threat
        • 2.Bxe6#
        • 2.Qxd6#
      • 1...Rxc7
        • 2.Qxd6#
      • 1...Rxe7
        • 2.Qxd6#
      • 1...Bxe7
        • 2.Bxe6#
      • 1...Sxa2
        • 2.Qa4#
        • 2.Qxd6#
      • 1...Sxh2
        • 2.Se5#
        • 2.Bxe6#
      • 1...Sxf6
        • 2.Qxd6#
      • 1...Sc2
        • 2.Qxd6#
      • 1...Sc6
        • 2.Qxd6#
      • 1...Sd5
        • 2.Qa4#
      • 1...Se3
        • 2.Se5#
        • 2.Qxd6#
      • 1...Se5
        • 2.Sxe5#
      • 1...d5
        • 2.Sc5#
      • 1...e5
        • 2.Qxg4#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 8
    • REMOVED MATES = 5
  • Sets
    • S(a);OGATE,XB(C)::QAB(F)
    • S(a);OGATE::QAB(F)
    • S(a);OGATE,XS(E)::QAB(F)
    • S(a);OGATE,XS(H)::QAB(F)
    • P(e);N_GUARD::S(H)
  • Tries
    • Try
      • S(E);CHECK
      • Vars
        • P(c);XS(E)::QAR(F)+S(H),DCHECK
      • Refutation
        • S(b);XS(E)
  • Actual
    • S(H);P_PINP(c)
    • Threat
      • DUALS(2)
    • Vars
      • R(g);XP(J)::QAR1(F),XP(c)
      • R(h);XS(H)::QAR1(F),XP(c)
      • B(i);P_PINP(I),XS(H)::B(C),XP(d)
      • S(b);XP(I)::QAR1(F),XP(c)
      • S(a);::QAR1(F),XP(c)
      • S(a);N_SPINP(c),OGATE::QAB(F)
      • S(b);N_GUARD::S(E),XS(b)
      • P(c);::S(E)
      • P(d);OGATEB::QAB(F),XS(b)
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