MESON Chess Problem Database

Problem Display
PID: 202934 (1rR1RN2/3p1p2/p1N5/3kP2p/2b3nb/B1Pn1K2/3QPpBp/4qr2 w - - 0 1)

Eaton, Vincent Lanius

The Observer, 1951

(First published on Sun Mar 25 1951)

1rR1RN2/3p1p2/p1N5/3kP2p/2b3nb/B1Pn1K2/3QPpBp/4qr2

#2

11 + 14

15239 Valois Notebooks 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Qxd2
      • 2.e4#
    • 1...Qa1
      • 2.e4#
    • 1...Qb1
      • 2.e4#
    • 1...Qc1
      • 2.e4#
    • 1...Qxe2+
      • 2.Kxe2#
    • 1...Rb4
      • 2.Sxb4#
    • 1...Ra8
      • 2.Sb4#
    • 1...Ba2
      • 2.Qxd3#
    • 1...Bb3
      • 2.Qxd3#
    • 1...Bb5
      • 2.Sb4#
    • 1...Bg3
      • 2.Kxg3#
    • 1...Bg5
      • 2.Kg3#
    • 1...Bf6
      • 2.Kg3#
    • 1...Be7
      • 2.Kg3#
    • 1...Bd8
      • 2.Kg3#
    • 1...Se3
      • 2.Kxe3#
    • 1...Sxe5+
      • 2.Rxe5#
    • 1...Sh6
      • 2.Ke3#
  • Keys
    • 1.Qg5!
      • threat
        • 2.Se7#
      • 1...Qxe2+
        • 2.Kxe2#
      • 1...Sdxe5+
        • 2.Kf4#
      • 1...Sgxe5+
        • 2.Ke3#
      • 1...Qxc3
        • 2.e4#
      • 1...Bxg5
        • 2.Kg3#
      • 1...dxc6
        • 2.Red8#
      • 1...f5
        • 2.Qg8#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 1
    • ADDED MATES = 4
    • REMOVED MATES = 15
  • Sets
    • Q(a);N_GUARD,N_SPINS(e),XQ(A)::P(B)
    • Q(a);N_GUARD::P(B)
    • Q(a);CHECK,XP(B)::B(C)+K(F),XQ(a)
    • R(n);N_GUARD::S(H),XR(n)
    • R(n);N_GUARD::S(H)
    • B(f);N_GUARD::QAR2(A),XS(e)
    • B(f);S_CUTR(n)::S(H)
    • B(h);::B(C)+K(F),XB(h)
    • B(h);::B(C)+K(F)
    • S(g);::B(C)+K(F),XS(g)
    • S(g);CHECK,OGATE,XP(G)::R1(J),XS(g)
    • S(g);::B(C)+K(F)
  • Actual
    • Q(A);N_PINS(e)
    • Threat
      • S(H)
    • Vars
      • Q(a);CHECK,XP(B)::B(C)+K(F),XQ(a)
      • S(e);CHECK,P_SPINS(e),XP(G)::B(C)+K(F)
      • S(g);CHECK,P_SPINS(g),XP(G)::B(C)+K(F)
      • Q(a);N_GUARD,XP(E)::P(B)
      • B(h);XQ(A)::B(C)+K(F)
      • P(l);OGATEB,XS(H)::R(J)
      • P(m);OGATEB::QAB(A)
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