MESON Chess Problem Database

Problem Display
PID: 211142 (5B2/1p6/1r3pK1/1n1p1Q2/1n1kN3/1PrqNP2/5P2/2bR4 w - - 0 1)

Ellerman, Arnoldo

The Observer, 1922

(First published on Tue Jan 29 1929)

5B2/1p6/1r3pK1/1n1p1Q2/1n1kN3/1PrqNP2/5P2/2bR4

#2

9 + 10

15239 Valois Notebooks 2020

SOLUTION

  • SOUND
  • Sets
    • 1...Rxb3
      • 2.Bc5#
    • 1...Rc5
      • 2.Bxc5#
    • 1...Sa2
      • 2.Qxd5#
    • 1...Sc2
      • 2.Qxd5#
    • 1...Sa6
      • 2.Qxd5#
    • 1...Sc6
      • 2.Qxd5#
    • 1...Sd6
      • 2.Qxf6#
    • 1...dxe4
      • 2.Qxe4#
  • Tries
    • 1.Rxd3+?
      • 1...Rxd3
        • 2.Bc5#
      • 1...Sxd3
        • 2.Qxd5#
      • 1...Kxd3!
  • Keys
    • 1.Qf4!
      • threat
        • 2.Sf5#
      • 1...f5+
        • 2.Sf6#
      • 1...Qxd1
        • 2.Sc5#
      • 1...Rxb3
        • 2.Bc5#
      • 1...Bxe3
        • 2.fxe3#
      • 1...dxe4
        • 2.Qxe4#
      • 1...Qd2
        • 2.Sc5#
      • 1...Sd6
        • 2.Qxf6#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 4
    • REMOVED MATES = 5
  • Sets
    • R(b);N_GUARD,XP(C)::B(I)
    • R(b);N_GUARD::B(I),XR(b)
    • S(d);N_GUARD::QAR1(G),XP(g)
    • S(f);S_CUTR(h)::QAB(G),XP(i)
    • P(g);OGATE,XS(F)::QAR1(G),XP(g)
  • Tries
    • Try
      • R(A);CHECK,XQ(c)
      • Vars
        • R(b);SBLOCK,XR(A)::B(I)
        • S(d);SBLOCK,XR(A)::QAR1(G),XP(g)
      • Refutation
        • K(e);P-FLIGHT,XR(A)
  • Actual
    • Q(G);P_SPINS(F)
    • Threat
      • S(D)
    • Vars
      • P(i);CHECK,N_PINS(F)::QAR(G)+S(F)
      • Q(c);N_PINS(F),N_SPINQ(c),XR(A)::QAR(G)+S(F)
      • R(b);N_GUARD,XP(C)::B(I)
      • B(a);OGATE,XS(D)::P(B),XB(a)
      • P(g);OGATE,P_SPINP(g),XS(F)::QAR1(G),XP(g)
      • Q(c);N_PINS(F)::QAR(G)+S(F)
      • S(f);S_CUTR(h)::QAB(G),XP(i)
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