MESON Chess Problem Database

Problem Display
PID: 177893 (B2RK3/5N1b/2r1pP1B/ppr1P3/4k2N/1Q2P1P1/6pp/b3nn2 w - - 0 1)

Lukyanov, Valentin Volodimirovich

2nd HM., Sahs (Latvia), 1984

B2RK3/5N1b/2r1pP1B/ppr1P3/4k2N/1Q2P1P1/6pp/b3nn2

#2

11 + 12

5454 Near Snap 2018
6490 yacpdb 2018

SOLUTION

  • SOUND
  • Sets
    • 1...Rc3
      • 2.Rd4#
    • 1...Rxe5
      • 2.Sd6#
    • 1...Bd4
      • 2.Rxd4#
    • 1...Bxe5
      • 2.Sg5#
    • 1...Sc2
      • 2.Qd3#
    • 1...Sd3
      • 2.Qxd3#
    • 1...Sf3
      • 2.Qd3#
    • 1...Sxe3
      • 2.Qxe3#
  • Tries
    • 1.Bf4?
      • threat
        • 2.Sg5#
        • 2.Sd6#
      • 1...Rxe5
        • 2.Sd6#
      • 1...Bxe5
        • 2.Sg5#
      • 1...Sxe3
        • 2.Sg5#
        • 2.Qxe3#
      • 1...Rc3
        • 2.Sg5#
        • 2.Rd4#
      • 1...Rc4
        • 2.Sg5#
      • 1...Rd5
        • 2.Sg5#
      • 1...Bc3
        • 2.Sg5#
      • 1...Sf3
        • 2.Sd6#
        • 2.Qd3#
      • 1...Bg6!
    • 1.Qb1+?
      • 1...Rc2
        • 2.Bxc6#
      • 1...Sd3
        • 2.Qxd3#
      • 1...Sc2!
    • 1.Qc3?
      • threat
        • 2.Sg5#
        • 2.Rd4#
      • 1...Rxc3
        • 2.Rd4#
      • 1...Rxe5
        • 2.Rd4#
      • 1...Rc4
        • 2.Sg5#
      • 1...Rd5
        • 2.Sg5#
      • 1...Bg6
        • 2.Rd4#
      • 1...Sc2
        • 2.Sg5#
        • 2.Qd3#
      • 1...Sd3
        • 2.Rd4#
        • 2.Qxd3#
      • 1...Sf3
        • 2.Qd3#
      • 1...Bxc3!
    • 1.Qb4+?
      • 1...Rc4
        • 2.Bxc6#
      • 1...Bd4
        • 2.Rxd4#
        • 2.Qxd4#
      • 1...axb4!
  • Keys
    • 1.Qxe6!
      • threat
        • 2.Qg4#
      • 1...Rxe5
        • 2.Bxc6#
      • 1...Bxe5
        • 2.Rd4#
      • 1...Sxe3
        • 2.Sg5#
      • 1...Rd5
        • 2.Qxd5#
      • 1...Bd4
        • 2.Rxd4#
      • 1...Bf5
        • 2.Qxf5#
      • 1...Sd3
        • 2.Sd6#

Anticipated by 17967(1952)

FEATURES

  • Static
    • TYPE = THREAT
    • CHANGED MATES = 4
    • ADDED MATES = 2
    • REMOVED MATES = 3
  • Sets
    • R(i);S_CUTB(a)::R1(J)
    • R(i);SBLOCK,XP(E)::S(H)
    • B(a);N_GUARD::R1(J),XB(a)
    • B(a);SBLOCK,XP(E)::S(H)
    • S(b);N_GUARD::QAB1(A)
    • S(b);N_GUARD::QAB1(A),XS(b)
    • S(c);OGATE,XP(B)::QAR1(A),XS(c)
  • Tries
    • Try
      • B(G);
      • Threat
        • DUALS(2)
      • Vars
        • R(i);XP(E)::S(H)
        • B(a);XP(E)::S(H)
        • R(i);::S(H)
        • R(i);N_SPINR(j)::S(H)
        • B(a);::S(H)
      • Refutation
        • B(l);P_PINS(H)
    • Try
      • Q(A);CHECK
      • Vars
        • R(i);N_SPINR(j),P_SPINR(i)::B(I),XR(j)
        • S(b);N_GUARD,P_SPINS(b)::QAB1(A),XS(b)
      • Refutation
        • S(b);P_SPINS(b)
    • Try
      • Q(A);
      • Threat
        • DUALS(2)
      • Vars
        • R(i);XQ(A)::R1(J)
        • R(i);XP(E)::R1(J)
        • R(i);::S(H)
        • R(i);N_SPINR(j)::S(H)
        • B(l);P_PINS(H)::R1(J)
        • S(b);N_GUARD::QAB1(A)
      • Refutation
        • B(a);XQ(A)
    • Try
      • Q(A);CHECK
      • Vars
        • R(i);N_SPINR(j),P_SPINR(i)::B(I),XR(j)
      • Refutation
        • P(g);XQ(A)
  • Actual
    • Q(A);XP(k)
    • Threat
      • QAR2(A)
    • Vars
      • R(i);N_GUARD,N_SPINR(j),P_PINQ(A),P_SPINR(i),XP(E)::B(I),XR(j)
      • B(a);N_GUARD,P_SPINB(a),XP(E)::R1(J)
      • S(c);SBLOCK,XP(B)::S(H)
      • R(i);N_GUARD,N_SPINR(j)::QAB1(A),XR(i)
      • B(a);N_GUARD::R1(J),XB(a)
      • B(l);N_GUARD::QAB1(A),XB(l)
      • S(b);SBLOCK::S(H)
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