MESON Chess Problem Database
Problem Display
PID: 192767 (7B/3p4/2pp2K1/2N1q2Q/1P1kP3/1B2R1p1/3r2N1/8 w - - 0 1)
Allen, Frederick B
The Observer, 1939
(First published on Sun Oct 1 1939)
#2
9 + 7
| 15239 | Valois Notebooks | 2019 |
SOLUTION
- SOUND
- Sets
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Qxh8
- 2.Qxh8#
- 1...Rd1
- 2.Qxd1#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...Rxg2
- 2.Rd3#
- 1...Rd3
- 2.Rxd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Qf6+
- Tries
- 1.Kh6?
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rd1
- 2.Qxd1#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Qxh8+!
- 1...Qf6+
- 1.Kf7?
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Qxh8
- 2.Qxh8#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rd1
- 2.Qxd1#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rf2+!
- 1...Qf6+
- 1.Kh7?
- 1...Qg7+
- 2.Bxg7#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Qf6
- 2.Bxf6#
- 1...Rd1
- 2.Qxd1#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Qxh8+!
- 1...Qg7+
- 1.Ba2?
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Qxh8
- 2.Qxh8#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rd1
- 2.Qxd1#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rxa2!
- 1...Qf6+
- 1.Bd5?
- threat
- 2.Sb3#
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rb2
- 2.Rd3#
- 1...cxd5!
- threat
- 1.Bf7?
- threat
- 2.Sb3#
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rb2
- 2.Rd3#
- 1...d5!
- threat
- 1.Bg8?
- threat
- 2.Sb3#
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rb2
- 2.Rd3#
- 1...d5!
- threat
- 1.Bf6?
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rd1
- 2.Qxd1#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Qxf6+!
- 1...Rxg2
- 1.Bg7?
- 1...Qf6+
- 2.Bxf6#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rd1
- 2.Qxd1#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Qxg7+!
- 1...Qf6+
- 1.Rc3?
- threat
- 2.Rc4#
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Qxe5#
- 1...Rc2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Kxc3!
- threat
- 1.Rf3?
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Qxh8
- 2.Qxh8#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rd1!
- 1...Qf6+
- 1.Rxg3?
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Qxh8
- 2.Qxh8#
- 1...dxc5
- 2.Qxe5#
- 1...Rd3
- 2.Rxd3#
- 1...Rd1
- 2.Qxd1#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...d5
- 2.Bxe5#
- 2.Qxe5#
- 1...Rxg2!
- 1...Qf6+
- 1.Qe2?
- threat
- 2.Qc4#
- 2.Qxd2#
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Rxe2
- 2.Rd3#
- 1...Rd3
- 2.Rxd3#
- 2.Qxd3#
- 1...Rd1
- 2.Qxd1#
- 2.Qc4#
- 2.Qb2#
- 1...Ra2
- 2.Rd3#
- 2.Qd3#
- 2.Qc4#
- 1...Rb2
- 2.Rd3#
- 2.Qd3#
- 2.Qc4#
- 2.Qxb2#
- 1...Rc2
- 2.Rd3#
- 2.Qd3#
- 1...d5
- 2.Qxd2#
- 1...Qxh8!
- threat
- 1.Kh6?
- Keys
- 1.Qg4!
- 1...Qf6+
- 2.Bxf6#
- 1...Qg7+
- 2.Bxg7#
- 1...Qxh8
- 2.e5#
- 1...Rxg2
- 2.Rd3#
- 1...dxc5
- 2.Qxd7#
- 1...Rd3
- 2.Rxd3#
- 1...Rd1
- 2.Qxd1#
- 1...Ra2
- 2.Rd3#
- 1...Rb2
- 2.Rd3#
- 1...Rc2
- 2.Rd3#
- 1...Re2
- 2.Rd3#
- 1...Rf2
- 2.Rd3#
- 1...d5
- 2.exd5#
- 1...Qf6+
- 1.Qg4!
FEATURES
- Static
- TYPE = MUTATE
- CHANGED MATES = 1
- ADDED MATES = 2
- REMOVED MATES = 0
- Sets
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- Q(d);N_SPINQ(d),OGATE,XB(I)::QAB(G),XQ(d)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- Tries
- Try
- K(H);P-FLIGHT
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- Q(d);CHECK,N_SPINQ(d),XB(I)
- Try
- K(H);S_FLIGHT
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- Q(d);N_SPINQ(d),OGATE,XB(I)::QAB(G),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- R(a);CHECK
- Try
- K(H);S_FLIGHT
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- Q(d);OGATEB::B(I),XQ(d)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- Q(d);CHECK,N_SPINQ(d),XB(I)
- Try
- B(B);
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- Q(d);N_SPINQ(d),OGATE,XB(I)::QAB(G),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- R(a);XB(B)
- Try
- B(B);
- Threat
- S(F)
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- P(e);XB(B)
- Try
- B(B);
- Threat
- S(F)
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- P(f);
- Try
- B(B);
- Threat
- S(F)
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- P(f);
- Try
- B(I);
- Vars
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- Q(d);CHECK,N_SPINQ(d),XB(I)
- Try
- B(I);
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- Q(d);CHECK,N_SPINQ(d),XB(I)
- Try
- R(C);
- Threat
- R1(C)
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- P(f);N_GUARD,XS(F)::QAB1(G),XQ(d)
- R(a);N_GUARD::R1(C)
- Refutation
- K(c);S_FLIGHT,XR(C)
- Try
- R(C);
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- Q(d);N_SPINQ(d),OGATE,XB(I)::QAB(G),XQ(d)
- R(a);N_GUARD,XS(A)::R1(C)
- P(f);N_GUARD,XS(F)::QAB1(G),XQ(d)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- R(a);
- Try
- R(C);XP(b)
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- Q(d);N_SPINQ(d),OGATE,XB(I)::QAB(G),XQ(d)
- P(f);N_GUARD,XS(F)::QAB1(G),XQ(d)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- Refutation
- R(a);P_PINR(C),XS(A)
- Try
- Q(G);
- Threat
- DUALS(2)
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- R(a);N_GUARD,XQ(G)::R1(C)
- P(f);::QAR2(G),XR(a)
- Refutation
- Q(d);N_SPINQ(d),XB(I)
- Try
- Actual
- Q(G);
- Vars
- Q(d);CHECK,OGATEB::B(I),XQ(d)
- Q(d);N_SPINQ(d),OGATE,XB(I)::QAR(G)+P(E)
- R(a);N_GUARD,XS(A)::R1(C)
- P(f);OGATEB,XS(F)::QAR(G),XP(g)
- R(a);N_GUARD::R1(C),XR(a)
- R(a);OGATEB::QAR(G),XR(a)
- R(a);N_GUARD::R1(C)
- P(f);OGATE::QAR(G)+P(E),XP(f)
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).