Meson Chess Problem Database

Blake, Percy Francis

1st Prize, The Observer, 1920

(First published on Sun Jul 25 1920)

8 + 12

3360	Simple Two-move Themes	1924
887	Mate in Two Moves	1931
56	The Problemist	1937
56	The Problemist	2003
5293	A selection of chess problems by G. C. Alvey	2004
15239	Valois Notebooks	2020

Static
- TYPE = THREAT
- CHANGED MATES = 1
- ADDED MATES = 2
- REMOVED MATES = 10
Sets
- Q(k);XR(F)::S(C),XQ(k)
- R(c);N_GUARD::R(F),XP(e)
- R(c);N_GUARD,XB(A)::R(F),XP(e)
- B(b);N_GUARD::QAB1(D)
- B(b);N_GUARD::QAB1(D),XB(b)
- S(a);S_CUTB(b)::QAB1(D)
- S(g);N_GUARD::QAR1(D)
- S(g);N_GUARD::QAR1(D),XS(g)
- P(e);OGATE,XS(C)::QAB1(D),XP(e)
- P(e);S_CUTR(c)::R(F)
- P(i);OGATEB::B(H)
Tries
- Try
  - S(G);CHECK,XB(l)
  - Vars
    - S(g);XS(G)::QAR1(D)
  - Refutation
    - Q(k);XS(G)
- Try
  - B(H);CHECK
  - Vars
    - S(a);XB(H)::QAB1(D)
  - Refutation
    - B(b);XB(H)
- Try
  - R(E);CHECK
  - Vars
    - S(g);P_SPINS(g)::QAR1(D)
    - P(i);P_SPINP(i),S_CUTP(j),S_CUTS(g)::B(H)
  - Refutation
    - P(j);P_SPINP(j)
- Try
  - Q(D);CHECK
  - Vars
    - P(i);S_CUTS(g),XQ(D)::B(H)
    - P(i);P_SPINP(i),S_CUTS(g)::B(H)
  - Refutation
    - S(g);P_SPINS(g)
Actual
- Q(D);
- Threat
  - S(C)
- Vars
  - Q(k);XR(F)::S(C),XQ(k)
  - P(e);OGATE,XS(C)::QAB1(D),XP(e)
  - P(i);OGATEB::B(H)
  - R(c);N_GUARD::R(F),XP(e)
  - B(b);SBLOCK::S(G)
  - S(a);OGATE::QAB(D),XB(b)
  - S(a);N_GUARD,S_CUTB(b)::B(H)

MESON Chess Problem Database