1r2kb1r/p1p1pp1p/1n6/1P1p2p1/1P1P4/B1q1PPK1/2P1Q1P1/1R3BR1 w k - 5 21
FEN state: 1r2kb1r/p1p1pp1p/1n6/1P1p2p1/1P1P4/B1q1PPK1/2P1Q1P1/1R3BR1 w k - 5 21 ; Best move: b1b3
The current state of the chess board is: Black rook at b8, black king at e8, black bishop at f8 and black rook at h8. Black pawn at a7, black pawn at c7, black pawn at e7, black pawn at f7 and black pawn at h7. Black knight at b6. White pawn at b5, black pawn at d5 and black pawn at g5. White pawn at b4 and white pawn at d4. White bishop at a3, black queen at c3, white pawn at e3, white pawn at f3 and white king at g3. White pawn at c2, white queen at e2 and white pawn at g2. White rook at b1, white bishop at f1 and white rook at g1. Black kingside is the only castle move available. Half move number is 5. Full move number is 21. White to move.