Clark reached ten ranking tournament quarter-finals in his career, but never progressed any further.

[1] He won two non-ranking events, defeating Ray Reardon in the final of the European Grand Masters in 1990 and Andy Hicks in the Pontins Professional in 1997.

[2] He retired as a pro player at a relatively young age, due to neck problems, and is now a tournament director.

[3] He has also helped with equipment maintenance (e.g. checking the replacement cloths) at the World Snooker Championship.

[4] In November 2017, Belgian player Luca Brecel was forced to borrow clothes from Clark and fellow player Michael White after lifting the wrong suitcase at an airport in Shanghai.