r1bq1br1/p1pk4/8/1p1pp2p/1Q3P2/1PPPP2p/P2N1Kn1/R1B2BNR w - - 0 21
FEN state: r1bq1br1/p1pk4/8/1p1pp2p/1Q3P2/1PPPP2p/P2N1Kn1/R1B2BNR w - - 0 21 ; Best move: b4b5
The current state of the chess board is: Black rook at a8, black bishop at c8, black queen at d8, black bishop at f8 and black rook at g8. Black pawn at a7, black pawn at c7 and black king at d7. Black pawn at b5, black pawn at d5, black pawn at e5 and black pawn at h5. White queen at b4 and white pawn at f4. White pawn at b3, white pawn at c3, white pawn at d3, white pawn at e3 and black pawn at h3. White pawn at a2, white knight at d2, white king at f2 and black knight at g2. White rook at a1, 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 0. Full move number is 21. White to move.