% Francois Labelle & computer, January 24, 2004 % All 30 at home PG-4.5 with exactly 2 solutions. % They are all SPGs. % Comment by Joost de Heer (January 28, 2004): % % No acceptable double-solution proofgame in 9 halfmoves. % % r1bqkbnr/pp1ppppp/8/8/8/8/PPP1PPPP/RN1QKBNR % SPG 4.5 (2 solutions) % % 1. d4 Nc6 2. Bf4 Nd4 3. Bc7 Qc7 4. Qd4 Qd8 5. Qd1 % 1. d4 c5 2. Bf4 cd4 3. Bb8 Rb8 4. Qd4 Ra8 5. Qd1 % % These two are somewhat interesting, because there are two different % black switchbacks, but the play is too repetitive to be 'publishable'. (Forsyth-Edwards Notation, followed by the same list in ascii diagrams) SPG-4.5: rnbqkb1r/pppppppp/8/8/8/8/PPP2PPP/1NBQKBNR 1nbqkbnr/1ppppppp/8/8/8/8/P1PPPPPP/1NBQKBNR rnb1kbnr/ppp1pppp/8/8/8/8/1P1PPPPP/1NBQKBNR rnb1kbnr/ppp1pppp/8/8/8/8/1PPP1PPP/1NBQKBNR rnbqkb1r/pppppppp/8/8/8/8/PPPPPP1P/R1BQKBNR r1bqkbnr/pppppppp/8/8/8/8/PPPP1PPP/RNBQK1NR rnbqkbnr/3ppppp/8/8/8/8/1PPPPPPP/RNBQKBNR r1bqkbnr/pppppppp/8/8/8/8/PPPPP1PP/RNBQKB1R r1bqkbnr/pppppppp/8/8/8/8/P1PPPPPP/RNBQKB1R rnbqkbnr/pppp1ppp/8/8/8/8/P1P1PPPP/RNBQKBNR rnb1kbnr/ppp1pppp/8/8/8/8/P2PPPPP/RNBQKBNR r1bqkbnr/pppppppp/8/8/8/8/P2PPPPP/RNBQKBNR rnbqk1nr/pppp1ppp/8/8/8/8/PPPPP1PP/RNBQKBNR rnb1kbnr/ppp1pppp/8/8/8/8/PP1PPPPP/RNBQKBNR rnbqkb1r/p1pppppp/8/8/8/8/PP1PPPPP/RNBQKBNR rnbqkb1r/1ppppppp/8/8/8/8/PP1PPPPP/RNBQKBNR r1bqkbnr/pppppp1p/8/8/8/8/P1PPPPPP/RNBQKBNR r1bqkbnr/pppp1ppp/8/8/8/8/P1PPPPPP/RNBQKBNR rnbqkb1r/p1pppppp/8/8/8/8/PPPPPP2/RNBQKBNR rnbqkbnr/ppppp3/8/8/8/8/PPPPPPP1/RNBQKBNR rnb1kbnr/pppp1ppp/8/8/8/8/PPPPPPP1/RNBQKBNR rnbqkb1r/pppppppp/8/8/8/8/PPPPP2P/RNBQKBNR r1bqkbnr/pppppppp/8/8/8/8/PPPP2PP/RNBQKBNR rnb1kbnr/ppp1pppp/8/8/8/8/P1PP1PPP/RNBQKBNR r1bqkbnr/pppppp1p/8/8/8/8/2PPPPPP/RNBQKBNR r1bqkbnr/pppppppp/8/8/8/8/PPP2PPP/RNBQKBN1 rnbqkbn1/ppppppp1/8/8/8/8/PPPPPP1P/RNBQKBN1 rnb1kbnr/ppp1pppp/8/8/8/8/PPPP1P1P/RNBQKBN1 r1bqkbnr/pppppppp/8/8/8/8/PPP1P1PP/RNB1KBNR r1bqkbnr/pp1ppppp/8/8/8/8/PPP1PPPP/RN1QKBNR _________________ _________________ _________________ _________________ | | | | | | r n b q k b . r | . n b q k b n r | r n b . k b n r | r n b . k b n r | | p p p p p p p p | . p p p p p p p | p p p . p p p p | p p p . p p p p | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | P P P . . P P P | P . P P P P P P | . P . P P P P P | . P P P . P P P | | . N B Q K B N R | . N B Q K B N R | . N B Q K B N R | . N B Q K B N R | |_________________|_________________|_________________|_________________| | | | | | | r n b q k b . r | r . b q k b n r | r n b q k b n r | r . b q k b n r | | p p p p p p p p | p p p p p p p p | . . . p p p p p | p p p p p p p p | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | P P P P P P . P | P P P P . P P P | . P P P P P P P | P P P P P . P P | | R . B Q K B N R | R N B Q K . N R | R N B Q K B N R | R N B Q K B . R | |_________________|_________________|_________________|_________________| | | | | | | r . b q k b n r | r n b q k b n r | r n b . k b n r | r . b q k b n r | | p p p p p p p p | p p p p . p p p | p p p . p p p p | p p p p p p p p | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | P . P P P P P P | P . P . P P P P | P . . P P P P P | P . . P P P P P | | R N B Q K B . R | R N B Q K B N R | R N B Q K B N R | R N B Q K B N R | |_________________|_________________|_________________|_________________| | | | | | | r n b q k . n r | r n b . k b n r | r n b q k b . r | r n b q k b . r | | p p p p . p p p | p p p . p p p p | p . p p p p p p | . p p p p p p p | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | P P P P P . P P | P P . P P P P P | P P . P P P P P | P P . P P P P P | | R N B Q K B N R | R N B Q K B N R | R N B Q K B N R | R N B Q K B N R | |_________________|_________________|_________________|_________________| | | | | | | r . b q k b n r | r . b q k b n r | r n b q k b . r | r n b q k b n r | | p p p p p p . p | p p p p . p p p | p . p p p p p p | p p p p p . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | P . P P P P P P | P . P P P P P P | P P P P P P . . | P P P P P P P . | | R N B Q K B N R | R N B Q K B N R | R N B Q K B N R | R N B Q K B N R | |_________________|_________________|_________________|_________________| | | | | | | r n b . k b n r | r n b q k b . r | r . b q k b n r | r n b . k b n r | | p p p p . p p p | p p p p p p p p | p p p p p p p p | p p p . p p p p | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | P P P P P P P . | P P P P P . . P | P P P P . . P P | P . P P . P P P | | R N B Q K B N R | R N B Q K B N R | R N B Q K B N R | R N B Q K B N R | |_________________|_________________|_________________|_________________| | | | | | | r . b q k b n r | r . b q k b n r | r n b q k b n . | r n b . k b n r | | p p p p p p . p | p p p p p p p p | p p p p p p p . | p p p . p p p p | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | . . . . . . . . | . . . . . . . . | | . . P P P P P P | P P P . . P P P | P P P P P P . P | P P P P . P . P | | R N B Q K B N R | R N B Q K B N . | R N B Q K B N . | R N B Q K B N . | |_________________|_________________|_________________|_________________| | | | | r . b q k b n r | r . b q k b n r | | p p p p p p p p | p p . p p p p p | | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | | . . . . . . . . | . . . . . . . . | | P P P . P . P P | P P P . P P P P | | R N B . K B N R | R N . Q K B N R | |_________________|_________________|