r1bqkr2/2pp1p1p/2nb4/pp2p1p1/PP1P2n1/R1PK4/3QPPPP/2B2BNR w q - 0 16
FEN state: r1bqkr2/2pp1p1p/2nb4/pp2p1p1/PP1P2n1/R1PK4/3QPPPP/2B2BNR w q - 0 16 ; Best move: a4b5
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8, black king at e8 and black rook at f8. Black pawn at c7, black pawn at d7, black pawn at f7 and black pawn at h7. Black knight at c6 and black bishop at d6. Black pawn at a5, black pawn at b5, black pawn at e5 and black pawn at g5. White pawn at a4, white pawn at b4, white pawn at d4 and black knight at g4. White rook at a3, white pawn at c3 and white king at d3. White queen at d2, white pawn at e2, white pawn at f2, white pawn at g2 and white pawn at h2. White bishop at c1, white bishop at f1, white knight at g1 and white rook at h1. Black queenside is the only castle move available. Half move number is 0. Full move number is 16. White to move.