As a method of recruiting to a politically sensitive post the sword in the stone proved effective. The belief at the time was that the top job could only be filled by a very special person. They were out there somewhere, it would be worth the wait for the right person. The jousting contest ,the winner of which earned the right to attempt to withdraw the sword from the stone was an irrelevant short listing process. The eventually successful candidate wasn't even eligible not being of noble birth. Merlin, clearly an HR wizard , recognised the process had to leave a clear winner with no room for dispute. Conventional wisdom at the time dictated that the post be filled by someone with strength, courage , the right background and the values of a knight( to protect the weak, to serve others and above all else to be "honourable"). The successful candidate was a young man who appeared to have non of these qualities. Which I assume was why the process had to be re run, the result being the same. It turned out to be a very good appointment.
Modern recruitment to politically sensitive top jobs still has a jousting process, still draws from a social elite and still requires the successful candidate to have that " magic quality". Of course the modern process lacks the transparency of a watching crowd or the requirement to repeat the trick. Having said this despite the apparent transparency and indisputable scientific method the outcome was fixed from the start. Merlin had already chosen his man, the process was just for show.
Blair McPherson author of An elephant in the room - about equality and diversity in the public sector published by Russell House www.blairmcpherson.co.uk