MESON Chess Problem Database
Problem Display
PID: 217853 (2bNk2q/3pBRR1/7p/1B1p3N/Q2Kn3/8/8/8 w - - 0 1)
O'Keefe, John James
British Chess Magazine, 1920
#2
8 + 7
SOLUTION
- SOUND
- Sets
- 1...Qxg7+
- 2.Sxg7#
- 1...Qh7
- 2.Rf8#
- 1...Qf8
- 2.Rxf8#
- 1...Qg8
- 2.Rxg8#
- 1...Ba6
- 2.Bxd7#
- 1...Bb7
- 2.Bxd7#
- 1...Sd2
- 2.Sf6#
- 1...Sf2
- 2.Sf6#
- 1...Sc3
- 2.Sf6#
- 1...Sg3
- 2.Sf6#
- 1...Sc5
- 2.Sf6#
- 1...Sg5
- 2.Sf6#
- 1...Sd6
- 2.Sf6#
- 1...Sf6
- 2.Sxf6#
- 1...Qxg7+
- Tries
- 1.Ke3?
- 1...Qxg7
- 2.Sxg7#
- 1...Qh7
- 2.Rf8#
- 1...Qf8
- 2.Rxf8#
- 1...Qg8
- 2.Rxg8#
- 1...Ba6
- 2.Bxd7#
- 1...Bb7
- 2.Bxd7#
- 1...Sd2
- 2.Sf6#
- 1...Sf2
- 2.Sf6#
- 1...Sc3
- 2.Sf6#
- 1...Sg3
- 2.Sf6#
- 1...Sc5
- 2.Sf6#
- 1...Sg5
- 2.Sf6#
- 1...Sd6
- 2.Sf6#
- 1...Sf6
- 2.Sxf6#
- 1...d4+!
- 1...Qxg7
- 1.Ke5?
- 1...Qxg7+
- 2.Sxg7#
- 1...Qh7
- 2.Rf8#
- 1...Qf8
- 2.Rxf8#
- 1...Qg8
- 2.Rxg8#
- 1...Ba6
- 2.Bxd7#
- 1...Bb7
- 2.Bxd7#
- 1...Sd2
- 2.Sf6#
- 1...Sf2
- 2.Sf6#
- 1...Sc3
- 2.Sf6#
- 1...Sg3
- 2.Sf6#
- 1...Sc5
- 2.Sf6#
- 1...Sg5
- 2.Sf6#
- 1...Sd6
- 2.Sf6#
- 1...Sf6
- 2.Sxf6#
- 1...d4!
- 1...Qxg7+
- 1.Bc6?
- 1...Qxg7+
- 2.Sxg7#
- 1...Ba6
- 2.Bxd7#
- 1...Qh7
- 2.Rf8#
- 1...Qf8
- 2.Rxf8#
- 1...Qg8
- 2.Rxg8#
- 1...Bb7
- 2.Bxd7#
- 1...Sd2
- 2.Sf6#
- 1...Sf2
- 2.Sf6#
- 1...Sc3
- 2.Sf6#
- 1...Sg3
- 2.Sf6#
- 1...Sc5
- 2.Sf6#
- 1...Sg5
- 2.Sf6#
- 1...Sd6
- 2.Sf6#
- 1...Sf6
- 2.Sxf6#
- 1...dxc6!
- 1...Qxg7+
- 1.Qa7?
- 1...Qxg7+
- 2.Sxg7#
- 1...Ba6
- 2.Bxd7#
- 2.Qxd7#
- 1...Qh7
- 2.Rf8#
- 1...Qf8
- 2.Rxf8#
- 1...Qg8
- 2.Rxg8#
- 1...Sd2
- 2.Sf6#
- 1...Sf2
- 2.Sf6#
- 1...Sc3
- 2.Sf6#
- 1...Sg3
- 2.Sf6#
- 1...Sc5
- 2.Sf6#
- 1...Sg5
- 2.Sf6#
- 1...Sd6
- 2.Sf6#
- 1...Sf6
- 2.Sxf6#
- 1...Bb7!
- 1...Qxg7+
- 1.Ke3?
- Keys
- 1.Qa8!
- 1...Qxg7+
- 2.Sxg7#
- 1...Bb7
- 2.Sxb7#
- 1...Qh7
- 2.Rf8#
- 1...Qf8
- 2.Rxf8#
- 1...Qg8
- 2.Rxg8#
- 1...Ba6
- 2.Sb7#
- 1...Sd2
- 2.Sf6#
- 1...Sf2
- 2.Sf6#
- 1...Sc3
- 2.Sf6#
- 1...Sg3
- 2.Sf6#
- 1...Sc5
- 2.Sf6#
- 1...Sg5
- 2.Sf6#
- 1...Sd6
- 2.Sf6#
- 1...Sf6
- 2.Sxf6#
- 1...Qxg7+
- 1.Qa8!
FEATURES
- Static
- TYPE = MUTATE
- CHANGED MATES = 2
- ADDED MATES = 0
- REMOVED MATES = 0
- Sets
- Q(g);CHECK,XR(G)::S(D),XQ(g)
- Q(g);N_GUARD,N_PINR(G)::R1(F)
- Q(g);N_GUARD,N_PINR(G)::R1(F),XQ(g)
- Q(g);N_PINR(G)::R(G),XQ(g)
- B(e);N_GUARD::B(C),XP(d)
- S(a);N_GUARD::S(D)
- S(a);N_GUARD,N_PINR(G)::S(D),XS(a)
- Tries
- Try
- K(B);N_SPINR(G),S_FLIGHT
- Vars
- Q(g);XR(G)::S(D),XQ(g)
- Q(g);N_GUARD::R1(F)
- Q(g);N_GUARD::R1(F),XQ(g)
- Q(g);N_GUARD::R(G),XQ(g)
- B(e);N_GUARD::B(C),XP(d)
- S(a);N_GUARD::S(D)
- S(a);N_GUARD::S(D),XS(a)
- Refutation
- P(b);CHECK
- Try
- K(B);S_FLIGHT
- Vars
- Q(g);CHECK,XR(G)::S(D),XQ(g)
- Q(g);N_GUARD,N_PINR(G)::R1(F)
- Q(g);N_GUARD,N_PINR(G)::R1(F),XQ(g)
- Q(g);N_PINR(G)::R(G),XQ(g)
- B(e);N_GUARD::B(C),XP(d)
- S(a);N_GUARD::S(D)
- S(a);N_GUARD,N_PINR(G)::S(D),XS(a)
- Refutation
- P(b);
- Try
- B(C);
- Vars
- Q(g);CHECK,XR(G)::S(D),XQ(g)
- B(e);N_GUARD::B(C),XP(d)
- Q(g);N_GUARD,N_PINR(G)::R1(F)
- Q(g);N_GUARD,N_PINR(G)::R1(F),XQ(g)
- Q(g);N_PINR(G)::R(G),XQ(g)
- S(a);N_GUARD::S(D)
- S(a);N_GUARD,N_PINR(G)::S(D),XS(a)
- Refutation
- P(d);XB(C)
- Try
- Q(A);
- Vars
- Q(g);CHECK,XR(G)::S(D),XQ(g)
- Q(g);N_GUARD,N_PINR(G)::R1(F)
- Q(g);N_GUARD,N_PINR(G)::R1(F),XQ(g)
- Q(g);N_PINR(G)::R(G),XQ(g)
- S(a);N_GUARD::S(D)
- S(a);N_GUARD,N_PINR(G)::S(D),XS(a)
- Refutation
- B(e);
- Try
- Actual
- Q(A);
- Vars
- Q(g);CHECK,XR(G)::S(D),XQ(g)
- B(e);::QAR(A)+S(H),XB(e)
- Q(g);N_GUARD,N_PINR(G)::R1(F)
- Q(g);N_GUARD,N_PINR(G)::R1(F),XQ(g)
- Q(g);N_PINR(G)::R(G),XQ(g)
- B(e);::QAR(A)+S(H)
- S(a);N_GUARD::S(D)
- S(a);N_GUARD,N_PINR(G)::S(D),XS(a)
Developed and maintained by Brian Stephenson.
Implemented with HTML5, MySQL, Perl (with, inter alia, CGI::Simple, HTML::Template & XML::LibXML) &
CSS/Javascript (jQuery, Bootstrap & DataTables).