According to the BBC website (http://www.bbc.co.uk/news/uk-13835245):
'In 2004, Gerry [McIlroy's dad] and three friends gathered £100 each and placed a £400 bet on Rory McIlroy to win The Open before he was 25. At the time, he was 15. The bookmakers gave them odds of 500-1.'
Jeff
Euler wrote:McIlroy looks very composed at the moment and is playing good percentage golf. If he carries on like this nobody will catch him.