r1bq1bnr/pp1kp1p1/2n5/2pp1p1p/1PN1N3/5PP1/P1PPP2P/R1BQKBR1 w Q - 0 10
FEN state: r1bq1bnr/pp1kp1p1/2n5/2pp1p1p/1PN1N3/5PP1/P1PPP2P/R1BQKBR1 w Q - 0 10 ; 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, black knight at g8 and black rook at h8. Black pawn at a7, black pawn at b7, black king at d7, black pawn at e7 and black pawn at g7. Black knight at c6. Black pawn at c5, black pawn at d5, black pawn at f5 and black pawn at h5. White pawn at b4, white knight at c4 and white knight at e4. White pawn at f3 and white pawn at g3. White pawn at a2, white pawn at c2, white pawn at d2, white pawn at e2 and white pawn at h2. White rook at a1, white bishop at c1, white queen at d1, white king at e1, white bishop at f1 and white rook at g1. White queenside is the only castle move available. Half move number is 0. Full move number is 10. White to move.