r1bq1r1k/3pbp1p/np2p1pn/p1p5/2PNP1P1/1P3P2/P2PNKBP/R1BQ3R w - - 5 13
FEN state: r1bq1r1k/3pbp1p/np2p1pn/p1p5/2PNP1P1/1P3P2/P2PNKBP/R1BQ3R w - - 5 13 ; Best move: d4b5
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8, black rook at f8 and black king at h8. Black pawn at d7, black bishop at e7, black pawn at f7 and black pawn at h7. Black knight at a6, black pawn at b6, black pawn at e6, black pawn at g6 and black knight at h6. Black pawn at a5 and black pawn at c5. White pawn at c4, white knight at d4, white pawn at e4 and white pawn at g4. White pawn at b3 and white pawn at f3. White pawn at a2, white pawn at d2, white knight at e2, white king at f2, white bishop at g2 and white pawn at h2. White rook at a1, white bishop at c1, white queen at d1 and white rook at h1. Both players have exhausted their castles. Half move number is 5. Full move number is 13. White to move.