How many 147s have there been at the Crucible?
BBC Sport looks at the history of 147 breaks at the World Snooker Championship.
[BBC] Ronnie O'Sullivan and Stephen Hendry share the record for the most maximum 147 breaks in World Snooker Championship history. O'Sullivan's trio of 147s in the history of the tournament came in 1997, 2003 and 2008. The first of those was the fastest ever recorded, at five minutes and eight seconds.
Stephen Hendry, who like O'Sullivan is a seven-time world champion, is the only other player to record multiple perfect breaks at the Crucible. They came at the 1995, 2009 and 2012 editions of the tournament. A total of 15 maximum breaks have been made in the main draw of the tournament.
Cliff Thorburn was the first player to ever record one in 1983, doing so in a second-round match against Terry Griffiths. There was then a nine-year wait for the second, with Jimmy White scoring one in 1992 in a first-round meeting with Tony Drago. Mark Allen was the most recent player to score a Crucible maximum, doing so in last year's tournament against Chris Wakelin.
Mark Williams, Ali Carter, John Higgins, Neil Robertson, Kyren Wilson and Mark Selby have also recorded perfect breaks at the tournament. Any player making a 147 at this year's World Championship stands to earn a bonus of £40,000. How often does a 147 lead to a win?