Ronnie O'Sullivan (L) of Britain reacts during the second round of World Snooker Championship against Ali Carter (R) of Britain at the Crucible Theatre in Sheffield, April 27, Britain, 2013.(Xinhua/Wang Zijiang) 

Ali Carter of Britain competes during second round of World Snooker Championship against Ronnie O'Sullivan of Britain at the Crucible Theatre in Sheffield, April 27, Britain, 2013.(Xinhua/Wang Zijiang) 

Ronnie O'Sullivan (R) of Britain competes against Ali Carter of Britain during their second round of World Snooker Championship at the Crucible Theatre in Sheffield, April 27, Britain, 2013.(Xinhua/Wang Zijiang)