//black move to empty (queen example) d8-a5 (Qa5)
twoFens("r1bqkbnr/pp1pppp1/2n4p/8/3NP3/2N5/PPP2PPP/R1BQKB1R b KQkq - 0 5", "r1b1kbnr/pp1pppp1/2n4p/q7/3NP3/2N5/PPP2PPP/R1BQKB1R w KQkq - 1 6")

//black move to empty (pawn) b7-b5 (b5)
twoFens("rnbqkbnr/ppp1pppp/8/2Pp4/8/8/PP1PPPPP/RNBQKBNR b KQkq - 0 2", "rnbqkbnr/p1p1pppp/8/1pPp4/8/8/PP1PPPPP/RNBQKBNR w KQkq b6 0 3")

//black capture (pawn x pawn) b5-a4 (bxa4)
twoFens("rnbqkbnr/p1p1pppp/8/1pPp4/P7/8/1P1PPPPP/RNBQKBNR b KQkq a3 0 3", "rnbqkbnr/p1p1pppp/8/2Pp4/p7/8/1P1PPPPP/RNBQKBNR w KQkq - 0 4")

//white move to empty (knight) g1-f3 (Nf3)
twoFens("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1", "rnbqkbnr/pppppppp/8/8/8/5N2/PPPPPPPP/RNBQKB1R b KQkq - 1 1")

//white capture (knight x pawn) f3-e5 (Nxe5)
twoFens("rnbqkbnr/pppp1ppp/8/4p3/8/5N2/PPPPPPPP/RNBQKB1R w KQkq e6 0 2", "rnbqkbnr/pppp1ppp/8/4N3/8/8/PPPPPPPP/RNBQKB1R b KQkq - 0 2")

//white e.p capture e5-d6 (exd6)
twoFens("rnbqkbnr/ppp1ppp1/7p/3pP3/8/8/PPPP1PPP/RNBQKBNR w KQkq d6 0 3", "rnbqkbnr/ppp1ppp1/3P3p/8/8/8/PPPP1PPP/RNBQKBNR b KQkq - 0 3")

//black e.p capture d4-e3 (dxe3)
twoFens("rnbqkbnr/ppp1pppp/8/8/P2pP3/8/1PPP1PPP/RNBQKBNR b KQkq e3 0 3", "rnbqkbnr/ppp1pppp/8/8/P7/4p3/1PPP1PPP/RNBQKBNR w KQkq - 0 4")

//black long castle e8-c8 (0-0-0)
twoFens("r3k2r/pbpqp1bp/1pnp1n2/5pp1/5PP1/1PNP1N2/PBPQP1BP/R3K2R b KQkq - 2 10", "2kr3r/pbpqp1bp/1pnp1n2/5pp1/5PP1/1PNP1N2/PBPQP1BP/R3K2R w KQ - 3 11")

//black short castle e8-g8 (0-0)
twoFens("r3k2r/pbpqp1bp/1pnp1n2/5pp1/5PP1/1PNP1N2/PBPQP1BP/R3K2R b KQkq - 2 10", "r4rk1/pbpqp1bp/1pnp1n2/5pp1/5PP1/1PNP1N2/PBPQP1BP/R3K2R w KQ - 3 11")

//white long castle e1-c1 (0-0-0)
twoFens("r3k2r/pbpqp2p/1pnp1n1b/5pp1/5PP1/1PNP1N2/PBPQP1BP/R3K2R w KQkq - 3 11", "r3k2r/pbpqp2p/1pnp1n1b/5pp1/5PP1/1PNP1N2/PBPQP1BP/2KR3R b kq - 4 11")

//white short castle e1-g1 (0-0)
twoFens("r3k2r/pbpqp2p/1pnp1n1b/5pp1/5PP1/1PNP1N2/PBPQP1BP/R3K2R w KQkq - 3 11", "r3k2r/pbpqp2p/1pnp1n1b/5pp1/5PP1/1PNP1N2/PBPQP1BP/R4RK1 b kq - 4 11")