Mark Selby and Ronnie O'Sullivan have been two of the most prominent figures in snooker over the past two decades, with their rivalry known for its intensity and skill. Despite the fierce competition on the table, Selby insists there was never any real issue between them off it. The pair have faced each other in numerous high-stakes matches, with Selby being the only player to beat O'Sullivan in the finals of all three Triple Crown tournaments—events that include the UK Championship, the Masters, and the World Championship. Their contrasting styles have made their encounters memorable; O'Sullivan once called Selby "The Torturer" in his autobiography, while more recently he dubbed him "Midnight Selby" due to the often long and drawn-out nature of their matches. O'Sullivan has long acknowledged Selby's strengths both on and off the table. In 2017, he praised Selby, saying he was a "good lad" and a "fierce competitor," adding that Selby's slower, more strategic play wasn't aimed at him personally. The two players also had an open and honest conversation about mental health in snooker during a 2022 Eurosport interview, which was widely praised for its sincerity. Selby later told Metro that any tension between them was exaggerated and that they never had a real problem. He described their interactions as respectful, even if they weren't close. As they've grown older, Selby has expressed deep respect for O'Sullivan, calling him "the greatest player to play the game." Recently, O'Sullivan defeated Selby in the quarter-finals of the Wuhan Open, winning 5-3. The match came after O'Sullivan had told Selby he was struggling with his game during the previous tournament, the China Open. Selby noted that O'Sullivan seemed to play at his best against him, only to struggle in his next match. He expressed some confusion about whether that was a compliment or not. Selby also observed that O'Sullivan, while still performing at a high level, sometimes plays below his usual standards, which he believes is a natural part of aging for top players. O'Sullivan has hinted that he might be in the final years of his professional career, which began in 1992. He has struggled to play at his best recently and has set a personal deadline of the 2028 World Championship to improve or else retire. Selby drew a parallel between O'Sullivan and another seven-time world champion, Stephen Hendry, who retired in 2012 after failing to reach the same heights he once did. Selby believes that top players, including O'Sullivan, often set high standards for themselves and can be their own harshest critics when they don't meet those goals.