r1q1k1r1/p2pn1b1/np5p/1PpBppp1/Q1P1PPP1/3b3N/P2P3P/RNB1K2R w KQ - 0 20
FEN state: r1q1k1r1/p2pn1b1/np5p/1PpBppp1/Q1P1PPP1/3b3N/P2P3P/RNB1K2R w KQ - 0 20 ; Best move: b5a6
The current state of the chess board is: Black rook at a8, black queen at c8, black king at e8 and black rook at g8. Black pawn at a7, black pawn at d7, black knight at e7 and black bishop at g7. Black knight at a6, black pawn at b6 and black pawn at h6. White pawn at b5, black pawn at c5, white bishop at d5, black pawn at e5, black pawn at f5 and black pawn at g5. White queen at a4, white pawn at c4, white pawn at e4, white pawn at f4 and white pawn at g4. Black bishop at d3 and white knight at h3. White pawn at a2, white pawn at d2 and white pawn at h2. White rook at a1, white knight at b1, white bishop at c1, white king at e1 and white rook at h1. White kingside and white queenside castles are available. Half move number is 0. Full move number is 20. White to move.