r1bqk2r/1ppppp2/p2b3n/n5pp/1P2PP1P/3P4/P1P1NKP1/R1BQ1BNR w k - 3 13
FEN state: r1bqk2r/1ppppp2/p2b3n/n5pp/1P2PP1P/3P4/P1P1NKP1/R1BQ1BNR w k - 3 13 ; Best move: b4a5
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 h8. Black pawn at b7, black pawn at c7, black pawn at d7, black pawn at e7 and black pawn at f7. Black pawn at a6, black bishop at d6 and black knight at h6. Black knight at a5, black pawn at g5 and black pawn at h5. White pawn at b4, white pawn at e4, white pawn at f4 and white pawn at h4. White pawn at d3. White pawn at a2, white pawn at c2, white knight at e2, white king at f2 and white pawn at g2. White rook at a1, white bishop at c1, white queen at d1, white bishop at f1, white knight at g1 and white rook at h1. Black kingside is the only castle move available. Half move number is 3. Full move number is 13. White to move.