Stephen Hendry holds the record for the most world titles in the modern era, having won the tournament seven times. Ray Reardon, Steve Davis, and Ronnie O'Sullivan have each won six titles; John Higgins and Mark Selby have won four; John Spencer and Mark Williams have both won three; and Alex Higgins has won two. The youngest champion in the tournament's history is Hendry, who won his first title in 1990, aged 21 years and 106 days. The oldest champion is Reardon, who won his last title in 1978, aged 45 years and 203 days. Steve Davis has made the most Crucible appearances, with 30 between 1979 and 2010, while O'Sullivan has made the most consecutive appearances, with 29 between 1993 and 2021. Eleven maximum breaks have been made in the history of the tournament, with Cliff Thorburn having achieved the first in 1983. A record 108 century breaks were made at the Crucible in 2021.