MESON Chess Problem Database

Problem Display
PID: 383 (8/4b1n1/3pbNB1/2nQ4/3PPk1P/4R3/K4NrR/2B3r1 w - - 0 1)

Vinje, Oskar E

The Observer, 1938

(First published on Sun Jan 30 1938)

8/4b1n1/3pbNB1/2nQ4/3PPk1P/4R3/K4NrR/2B3r1

#2

11 + 8

5088 How to Solve Chess Problems 1945
5064 100 Years of the American Two-move Chess Problem 1962
15239 Valois Notebooks 2019
5454 Near Snap 2021

SOLUTION

  • SOUND
  • Sets
    • 1...Rxf2+
      • 2.Rxf2#
    • 1...Rg4
      • 2.Sh3#
    • 1...Bg4
      • 2.Qg5#
    • 1...Bxd5+
      • 2.Sxd5#
    • 1...Sf5
      • 2.Sh5#
    • 1...Sh5
      • 2.Sxh5#
    • 1...Se8
      • 2.Sh5#
  • Tries
    • 1.Qxe6?
      • threat
        • 2.Sd5#
      • 1...Rxf2+
        • 2.Rxf2#
      • 1...Rg5
        • 2.Sh3#
      • 1...d5
        • 2.Sxd5#
        • 2.Qe5#
      • 1...Bxf6!
    • 1.e5?
      • threat
        • 2.Rf3#
      • 1...Rxf2+
        • 2.Rxf2#
      • 1...Bxd5+
        • 2.Sxd5#
      • 1...Se4!
  • Keys
    • 1.Bh5!
      • threat
        • 2.Rf3#
      • 1...Rxf2+
        • 2.Rxf2#
      • 1...Bxd5+
        • 2.Sxd5#
      • 1...Sxh5
        • 2.Sxh5#
      • 1...Rg4
        • 2.Sh3#
      • 1...Bg4
        • 2.Qg5#

Anticipated by 250098(1927)

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 0
    • ADDED MATES = 0
    • REMOVED MATES = 2
  • Sets
    • R(b);CHECK,OGATE,XS(C)::R(D),XR(b)
    • R(b);N_PINS(C)::S(C)
    • B(f);N_PINQ(I)::QAB1(I)
    • B(f);CHECK,XQ(I)::S(J),XB(f)
    • S(h);N_GUARD::S(J)
    • S(h);N_GUARD::S(J),XS(h)
  • Tries
    • Try
      • Q(I);N_SPINQ(I),XB(f)
      • Threat
        • S(J)
      • Vars
        • R(b);CHECK,OGATE,XS(C)::R(D),XR(b)
        • R(b);N_PINS(C)::S(C)
      • Refutation
        • B(g);XS(J)
    • Try
      • P(G);
      • Threat
        • B(A)+R(E),DCHECK
      • Vars
        • R(b);CHECK,OGATE,XS(C)::R(D),XR(b)
        • B(f);CHECK,XQ(I)::S(J),XB(f)
      • Refutation
        • S(d);
  • Actual
    • B(K);
    • Threat
      • B(A)+R(E),DCHECK
    • Vars
      • R(b);CHECK,OGATE,XS(C)::R(D),XR(b)
      • B(f);CHECK,XQ(I)::S(J),XB(f)
      • S(h);XB(K)::S(J),XS(h)
      • R(b);N_PINS(C)::S(C)
      • B(f);N_PINQ(I)::QAB1(I)
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