PRINCE HARRY’S SPARE HAS MADE J. R. MOEHRINGER the most famous ghostwriter in the world. Long before he took on an aggrieved prince, however, Moehringer worked with tennis royalty in ANDRE AGASSI, and their book Open remains perhaps the standout sports autobiography of the twenty-first century so far.

I’ve been lucky enough to ghost three major sporting figures myself: the rugby players and ( and respectively) and the jockey with . Along the way, I’ve learned that such books need to be five things if they’re to sing: five things which spell Getting the voice right is arguably the most important part of the process. An autobiography in which yours, the ghost’s, voice intrudes has failed in its first purpose.