Meson Chess Problem Database

Erokhin, Vladimir Alekseevich

Shedey, Sergey Oleksandrovich

1/2 Prize, Petrov MT, 1975

7 + 12

3771	FIDE Album (1974-1976)	1980

Static
- TYPE = THREAT
- CHANGED MATES = 1
- ADDED MATES = 3
- REMOVED MATES = 4
Sets
- Q(e);SBLOCK::S(F),XP(i)
- R(b);N_GUARD::QAB(A)
- R(b);N_GUARD::QAB(A),XR(b)
- S(c);SBLOCK::S(C)
- P(i);N_GUARD::R1(D)
- P(j);SBLOCK::S(F),XP(i)
Tries
- Try
  - B(B);XB(a)
  - Threat
    - DUALS(2)
  - Vars
    - P(j);XS(C)::QAB1(A)
    - R(b);::S(C)
  - Refutation
    - R(b);
- Try
  - B(B);
  - Threat
    - DUALS(2)
  - Vars
    - B(a);XB(B)::QAB1(A)
    - P(j);XS(C)::QAB1(A)
    - R(b);::S(C)
  - Refutation
    - R(b);
- Try
  - B(B);
  - Threat
    - QAB1(A)
  - Vars
    - R(b);S_CUTB(a)::S(C)
    - B(a);S_CUTR(b)::S(F),XP(i)
    - P(i);S_CUTR(b)::S(F)
  - Refutation
    - B(a);
- Try
  - B(B);
  - Threat
    - DUALS(2)
  - Vars
    - B(a);XB(B)::QAB1(A)
    - P(j);XS(C)::QAB1(A)
    - P(j);::QAB1(A)
    - Q(e);::QAB1(A)
    - B(a);S_CUTR(b)::S(F),XP(i)
    - B(a);::S(C)
  - Refutation
    - R(b);
- Try
  - R(D);CHECK
  - Refutation
    - Q(e);XR(D)
- Try
  - Q(A);CHECK
  - Vars
    - R(b);N_GUARD,P_SPINR(b)::QAB(A),XR(b)
  - Refutation
    - R(b);XQ(A)
- Try
  - Q(A);CHECK
  - Vars
    - P(i);N_GUARD,P_PINB(B),XQ(A)::R1(D)
    - P(i);N_GUARD,P_SPINP(i)::R1(D)
  - Refutation
    - S(k);P_SPINS(k)
Actual
- R(D);
- Threat
  - QAB1(A)
- Vars
  - K(g);P_SPINS(k),S_FLIGHT,XR(D)::S(F),XP(i)
  - Q(e);N_GUARD::S(C)
  - S(c);N_GUARD::R1(D),XS(c)
  - S(k);::S(C)
  - P(i);N_GUARD::R1(D)

MESON Chess Problem Database