A “turn up for the books” is a phrase used to describe an unusual event, usually regarding a change in a personality. For instance an alcoholic coming home sober would be a turn up for the books. The phrase originated with horse racing. A turn up for the books was an unfancied horse coming in first, or the favourite doing badly. The turf accountants or “bookies” would have to re-write their books taking in to account the surprising result.
Source: The Phrase Finder