MESON Chess Problem Database
Problem Display
PID: 11206 (8/6p1/pp4N1/rb1Q1B1K/pP1P3P/P1B1Np1n/2P1kP2/5Rn1 w - - 0 1)
Penrose, Lionel Sharples
Chess, 1937
#2
13 + 10
SOLUTION
- SOUND
- Sets
- 1...Bd3
- 2.Bxd3#
- 1...Bc4
- 2.Qxc4#
- 1...Bc6
- 2.Bd3#
- 2.Qc4#
- 1...Bd7
- 2.Bd3#
- 2.Qc4#
- 1...Be8
- 2.Bd3#
- 2.Qc4#
- 1...Sxf2
- 2.Re1#
- 1...Sf4+
- 2.Sxf4#
- 1...Sg5
- 2.Sf4#
- 1...Bd3
- Tries
- 1.Kg4?
- 1...Bd3
- 2.Bxd3#
- 1...Bc4
- 2.Qxc4#
- 1...Bc6
- 2.Bd3#
- 2.Qc4#
- 1...Bd7
- 2.Qc4#
- 1...Be8
- 2.Bd3#
- 2.Qc4#
- 1...Sf4
- 2.Sxf4#
- 1...Sg5
- 2.Sf4#
- 1...Sxf2+!
- 1...Bd3
- 1.Be1?
- 1...Sf4+
- 2.Sxf4#
- 1...Bd3
- 2.Bxd3#
- 1...Bc4
- 2.Qxc4#
- 1...Bc6
- 2.Bd3#
- 2.Qc4#
- 1...Bd7
- 2.Bd3#
- 2.Qc4#
- 1...Be8
- 2.Bd3#
- 2.Qc4#
- 1...Sg5
- 2.Sf4#
- 1...Sxf2!
- 1...Sf4+
- 1.Be4?
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Re1#
- 1...Bd3
- 2.Bxd3#
- 1...Bc6
- 2.Bd3#
- 1...Bd7
- 2.Bd3#
- 1...Be8
- 2.Bd3#
- 1...Sg5
- 2.Sf4#
- 1...Bc4!
- 1...Sf4+
- 1.Qe4?
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Sf4#
- 2.Re1#
- 1...Bd3
- 2.Qxd3#
- 1...Bc6
- 2.Qd3#
- 1...Bd7
- 2.Qd3#
- 1...Be8
- 2.Qd3#
- 1...Sg5
- 2.Sf4#
- 1...Bc4!
- 1...Sf4+
- 1.Qe6?
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Sf4#
- 2.Re1#
- 1...Bc4
- 2.Qxc4#
- 1...Bc6
- 2.Qc4#
- 1...Bd7
- 2.Qc4#
- 1...Be8
- 2.Qc4#
- 1...Sg5
- 2.Sf4#
- 1...Bd3!
- 1...Sf4+
- 1.Qf7?
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Re1#
- 1...Bc4
- 2.Qxc4#
- 1...Bc6
- 2.Qc4#
- 1...Bd7
- 2.Qc4#
- 1...Be8
- 2.Qc4#
- 1...Sg5
- 2.Sf4#
- 1...Bd3!
- 1...Sf4+
- 1.Qg8?
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Re1#
- 1...Bc4
- 2.Qxc4#
- 1...Bc6
- 2.Qc4#
- 1...Bd7
- 2.Qc4#
- 1...Be8
- 2.Qc4#
- 1...Sg5
- 2.Sf4#
- 1...Bd3!
- 1...Sf4+
- 1.Qxb5+?
- 1...axb5
- 2.Bd3#
- 1...Rxb5!
- 1...axb5
- 1.Qc5?
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Re1#
- 1...Bd3
- 2.Bxd3#
- 1...Bc4
- 2.Qxc4#
- 1...Bc6
- 2.Bd3#
- 2.Qc4#
- 1...Bd7
- 2.Bd3#
- 2.Qc4#
- 1...Be8
- 2.Bd3#
- 2.Qc4#
- 1...Sg5
- 2.Sf4#
- 1...bxc5!
- 1...Sf4+
- 1.Qe5?
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Sf4#
- 2.Re1#
- 1...Bd3
- 2.Bxd3#
- 1...Bc6
- 2.Bd3#
- 1...Bd7
- 2.Bd3#
- 1...Be8
- 2.Bd3#
- 1...Sg5
- 2.Sf4#
- 1...Bc4!
- 1...Sf4+
- 1.bxa5?
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Re1#
- 1...Bd3
- 2.Bxd3#
- 1...Bc4
- 2.Qxc4#
- 1...Bc6
- 2.Bd3#
- 2.Qc4#
- 1...Bd7
- 2.Bd3#
- 2.Qc4#
- 1...Be8
- 2.Bd3#
- 2.Qc4#
- 1...Sg5
- 2.Sf4#
- 1...bxa5!
- 1...Sf4+
- 1.Kg4?
- Keys
- 1.Qa2!
- 1...Sf4+
- 2.Sxf4#
- 1...Sxf2
- 2.Re1#
- 1...Bc4
- 2.Qxc4#
- 1...Bd3
- 2.cxd3#
- 1...Bc6
- 2.Qc4#
- 1...Bd7
- 2.Qc4#
- 1...Be8
- 2.Qc4#
- 1...Sg5
- 2.Sf4#
- 1...Sf4+
- 1.Qa2!
FEATURES
- Static
- TYPE = MUTATE
- CHANGED MATES = 1
- ADDED MATES = 3
- REMOVED MATES = 0
- Sets
- B(g);N_GUARD::B(K),XB(g)
- B(g);N_GUARD::QAB(J),XB(g)
- S(d);SBLOCK,XP(C)::R1(A)
- S(d);CHECK,N_GUARD::S(M),XS(d)
- S(d);N_GUARD::S(M)
- Tries
- Try
- K(L);S_FLIGHT
- Vars
- B(g);N_GUARD::B(K),XB(g)
- B(g);N_GUARD::QAB(J),XB(g)
- B(g);N_GUARD,P_PINB(K)::QAB(J)
- S(d);N_GUARD::S(M),XS(d)
- S(d);N_GUARD::S(M)
- Refutation
- S(d);CHECK,XP(C)
- Try
- B(E);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- B(g);N_GUARD::B(K),XB(g)
- B(g);N_GUARD::QAB(J),XB(g)
- S(d);N_GUARD::S(M)
- Refutation
- S(d);XP(C)
- Try
- B(K);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- S(d);SBLOCK,XP(C)::R1(A)
- B(g);N_GUARD,P_PINQ(J)::B(K),XB(g)
- B(g);N_GUARD,P_PINQ(J)::B(K)
- B(g);N_GUARD,P_PINQ(J),P_PINS(M)::B(K)
- S(d);N_GUARD::S(M)
- Refutation
- B(g);P_PINQ(J)
- Try
- Q(J);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- B(g);N_GUARD,P_PINB(K)::QAB1(J),XB(g)
- B(g);N_GUARD,P_PINB(K)::QAB1(J)
- B(g);N_GUARD,P_PINB(K),P_PINS(M)::QAB1(J)
- S(d);N_GUARD::S(M)
- Refutation
- B(g);P_PINB(K)
- Try
- Q(J);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- B(g);N_GUARD,P_PINB(K)::QAB(J),XB(g)
- B(g);N_GUARD,P_PINB(K)::QAB(J)
- B(g);N_GUARD,P_PINB(K),P_PINS(M)::QAB(J)
- S(d);N_GUARD::S(M)
- Refutation
- B(g);P_PINB(K)
- Try
- Q(J);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- S(d);SBLOCK,XP(C)::R1(A)
- B(g);N_GUARD,P_PINB(K)::QAB(J),XB(g)
- B(g);N_GUARD,P_PINB(K)::QAB(J)
- S(d);N_GUARD::S(M)
- Refutation
- B(g);P_PINB(K)
- Try
- Q(J);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- S(d);SBLOCK,XP(C)::R1(A)
- B(g);N_GUARD,P_PINB(K)::QAB(J),XB(g)
- B(g);N_GUARD,P_PINB(K)::QAB(J)
- B(g);N_GUARD,P_PINB(K),P_PINS(M)::QAB(J)
- S(d);N_GUARD::S(M)
- Refutation
- B(g);P_PINB(K)
- Try
- Q(J);CHECK,XB(g)
- Vars
- P(h);XQ(J)::B(K)
- Refutation
- R(f);P_PINB(K),XQ(J)
- Try
- Q(J);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- S(d);SBLOCK,XP(C)::R1(A)
- B(g);N_GUARD::B(K),XB(g)
- B(g);N_GUARD::QAB(J),XB(g)
- S(d);N_GUARD::S(M)
- Refutation
- P(i);XQ(J)
- Try
- Q(J);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- B(g);N_GUARD::B(K),XB(g)
- B(g);N_GUARD::B(K)
- B(g);N_GUARD,P_PINS(M)::B(K)
- S(d);N_GUARD::S(M)
- Refutation
- B(g);
- Try
- P(G);XR(f)
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- S(d);SBLOCK,XP(C)::R1(A)
- B(g);N_GUARD::B(K),XB(g)
- B(g);N_GUARD::QAB(J),XB(g)
- S(d);N_GUARD::S(M)
- Refutation
- P(i);XP(G)
- Try
- Actual
- Q(J);
- Vars
- S(d);CHECK,N_GUARD::S(M),XS(d)
- S(d);SBLOCK,XP(C)::R1(A)
- B(g);N_GUARD,P_PINB(K)::QAB(J),XB(g)
- B(g);OGATE,P_PINB(K)::QAR(J)+P(B),XB(g)
- B(g);N_GUARD,P_PINB(K)::QAB(J)
- B(g);N_GUARD,P_PINB(K),P_PINS(M)::QAB(J)
- S(d);N_GUARD::S(M)
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).