Complex sentence: Since the rook is positioned on the fifth file, it prevents the player from making the usual Mino castle, Central Rook's castle is often an Incomplete Mino (片美濃).
Split into simpler sentences: Since the rook is positioned on the fifth file, it prevents the player from making the usual Mino castle. Therefore, Central Rook's castle is often an Incomplete Mino (片美濃).