
The yardage book is the bible for both caddie and player at The Open. The moment the duo reach their ball, out come the yardage books. As a former caddie at Royal County Down and having looped in R&A events, I too know the importance of this little book. However, the book used by the players this week may prove substantially different to the one you've seen or used before.
The yardage book for Royal Portush and the 153rd Open Championship is one with a level of detail I've never seen before - but what makes it so different from the ones us mere mortals can buy in a regular pro shop?