A Turn Up For The Book is an agreeable surprise, but not automatically for all. It is a horseracing phrase at dates back a long way. A “book” is a bookmaker’s record of bets placed on a race. On certain occasions, favourites would be backed so heavily that a bookmaker chanced to lose his livelihood if the favourite won. At times like these it would be in the bookmaker’s interest for an unfancied horse with very few bets on it to win. It was quite common for favours to be called in at times and now and then certain owners would allow their champion horse to turn up and run under the name of an inferior one, and so beat the field and save a friendly bookmaker's business. Because of this, an unfancied horse racing well and surprising “everyone” by winning was known as a “turn up for the book” - it had turned up specifically to aid the bookmaker's book.