MESON Chess Problem Database

Problem Display
PID: 179691 (3b1N1R/RnPbkP2/4pr1n/2P2pPB/1K3Np1/8/8/8 w - - 0 1)

Kopnin, Aleksey Grigorevich

1st Prize, Sverdlovsk Ty., 1959

3b1N1R/RnPbkP2/4pr1n/2P2pPB/1K3Np1/8/8/8

#2

10 + 9

6490 yacpdb 2018

SOLUTION

  • SOUND
  • Sets
    • 1...Rxf7
      • 2.S8g6#
    • 1...Ba4
      • 2.c8S#
    • 1...Bb5
      • 2.c8S#
    • 1...Bc6
      • 2.c8S#
    • 1...Be8
      • 2.c8S#
      • 2.fxe8Q#
      • 2.fxe8R#
    • 1...Sa5
      • 2.c8S#
    • 1...Sxc5
      • 2.c8S#
    • 1...e5
      • 2.Sd5#
  • Tries
    • 1.S8g6+?
      • 1...Rxg6
        • 2.f8Q#
      • 1...Kxf7!
    • 1.cxd8Q+?
      • 1...Sxd8
        • 2.Rxd7#
      • 1...Kxd8!
    • 1.cxd8B+?
      • 1...Sxd8
        • 2.Rxd7#
      • 1...Kxd8!
  • Keys
    • 1.Sh7!
      • threat
        • 2.gxf6#
      • 1...Rxf7
        • 2.Sg6#
      • 1...Sxc5
        • 2.c8S#
      • 1...Rg6
        • 2.f8Q#
      • 1...Ba4
        • 2.cxd8Q#
      • 1...Bb5
        • 2.cxd8Q#
      • 1...Bc6
        • 2.cxd8Q#
      • 1...Bc8
        • 2.cxd8Q#
      • 1...Be8
        • 2.fxe8Q#
      • 1...Sg8
        • 2.fxg8S#

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 4
    • ADDED MATES = 4
    • REMOVED MATES = 2
  • Sets
    • R(d);N_GUARD,SBLOCK,XP(H)::S(I)
    • B(g);N_GUARD::P=S
    • S(f);S_CUTB(g)::P=S
    • S(f);S_CUTB(g),XP(C)::P=S
    • P(c);N_GUARD::S(B)
  • Tries
    • Try
      • S(I);CHECK
      • Vars
        • R(d);XS(I)::P=Q
      • Refutation
        • K(h);P-FLIGHT,XP(H)
    • Try
      • P(G);CHECK,XB(i)
      • Vars
        • S(f);OGATE,P_SPINB(g),XQ(G)::R1(F),XB(g)
      • Refutation
        • K(h);S_FLIGHT,XQ(G)
    • Try
      • P(G);CHECK,XB(i)
      • Vars
        • S(f);OGATE,P_SPINB(g),XB(G)::R1(F),XB(g)
      • Refutation
        • K(h);S_FLIGHT,XB(G)
  • Actual
    • S(I);
    • Threat
      • P(D),XR(d)
    • Vars
      • R(d);N_GUARD,SBLOCK,XP(H)::S(B)
      • S(f);S_CUTB(g),XP(C)::P=S
      • R(d);N_GUARD::P=Q
      • B(g);S_CUTS(f)::PXB(i)=Q
      • B(g);OGATE::PXB(g)=Q
      • S(e);OGATE::PXS(e)=S
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