r1bq2r1/pp1pk2p/nn4p1/2p1pp2/P3PPP1/1PP5/5K1P/RNB2BNR w - - 3 21
FEN state: r1bq2r1/pp1pk2p/nn4p1/2p1pp2/P3PPP1/1PP5/5K1P/RNB2BNR w - - 3 21 ; Best move: a4a5
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8 and black rook at g8. Black pawn at a7, black pawn at b7, black pawn at d7, black king at e7 and black pawn at h7. Black knight at a6, black knight at b6 and black pawn at g6. Black pawn at c5, black pawn at e5 and black pawn at f5. White pawn at a4, white pawn at e4, white pawn at f4 and white pawn at g4. White pawn at b3 and white pawn at c3. White king at f2 and white pawn at h2. White rook at a1, white knight at b1, white bishop at c1, white bishop at f1, white knight at g1 and white rook at h1. Both players have exhausted their castles. Half move number is 3. Full move number is 21. White to move.