It depends totally on the opening. You can be out of book and database far quicker than that for offbeat stuff, or in book far longer for popular openings. Ano

It depends totally on the opening. You can be out of book and database far quicker than that for offbeat stuff, or in book far longer for popular openings. Another distinction needs to be made between positions seen and positions played. Almost every viable position will have been seen in preparation well beyond 10 moves. But seeing them on the board is rarer.