Of course, barring fouls, the maximum number of points available in a single frame of snooker is 147. However, since the ‘miss’ rule was introduced to professional snooker, in September, 1995, players can, at the discretion of their opponent, be made to replay a shot indefinitely, conceding penalty points each time they do so. Thus, the potential for single-frame scores in excess, or well in excess, of 147 points is inherent to modern professional snooker.
For example, during a best-of-19-frame, first-round match in the World Snooker Championship at the Crucible Theatre, Sheffield in April, 1999, Welsh professional Dominic Dale accrued a single-frame score of 167 points. His total consisted of a single red, 44 penalty points conceded by his opponent, Nigel Bond, and a break of 122. Bond, though, won the match 10-6, before being beaten 13-11 by Ken Doherty in the second round.
Dale set a record that would last over 22 years, until it was finally broken by English professional Jimmy Robertson in what turned out to be the final frame of a best-of-seven-frame, last-64 match against former Welsh professional Lee Walker in the re-arranged Scottish Open at Venue Cymru, Llandudno in December, 2021. After potting a long red, Robertson rolled the cue ball tight behind the brown and Walker subsequently made nine unsuccessful attempts to hit a red, conceding 40 penalty points in the process. Later in the frame, Walker conceded another four penalty points, such that he trailed 45-6, but Robertson made a clearance of 133 to close out the match 4-1 and set a new single-frame record of 178 points. Robertson was subsequently beaten 4-3 by eventual runner-up Anthony McGill in the last 32.