Xu Si

Xu's first professional match was in qualifying for the Riga Masters where he lost 4–2 to Robbie Williams. However, in only his third tournament, the 2017 Indian Open, he beat Michael Georgiou, Robin Hull, Sean O'Sullivan, Ricky Walden and Dave Gilbert to reach the semi-final, where he lost to John Higgins 4–2.

Xu reached the 2nd round of the UK Championship beating Mark Davis 6–5, and also reached the 4th round of the Scottish Open and 3rd round of the Welsh Open. In the World Championship, he lost the first match to Chris Wakelin 10–4. Xu finished the season ranked 91, but was awarded the title 'Rookie of the Year'.[8]

Xu's second season saw a loss of form. He won only 6 matches and failed to win back-to-back matches in any tournament. His best win was a highly emotional match against Martin Gould in the China Championship qualifying round, which he won 5–4 on the final black. This result allowed him to play in the main event in Guangzhou, close to his hometown of Jieyang, allowing his relatives to see him play professional snooker for the first time. However, he lost to Noppon Saengkham.

In the World Championship Xu produced a magnificent display of scoring to beat Sean O'Sullivan, scoring ten 50+ breaks in successive frames to win the match 10–2. However, he could not repeat this form against Graeme Dott, losing 10–4. His ranking of 77 meant that he was relegated from the tour.

Xu Si came through the first event of the 2019 Q School by winning five matches to earn a two-year card on the World Snooker Tour for the 2019–20 and 2020–21 seasons.

Xu's third season was similar to his second, winning only 4 matches. It came to a premature end when the COVID-19 outbreak forced the suspension of the season. Xu returned to China and did not return for the resumption in July 2020, thereby missing the World Championship. His final ranking was 110.

For his fourth season, Xu made some technical changes, adopting the 'Sight Right' method. He also moved to the newly opened Ding Junhui Academy in Sheffield. His results were more consistent, reaching the 3rd round in the UK Championship and the English Open.

In World Championship qualification, Xu needed to win his first match to renew his professional tour card via the 1-year ranking list. His opponent was 7-times World Champion Stephen Hendry, in the third match of his comeback. After a nervous start, Xu won the last 6 frames of the match, with five 50+ breaks, to win 6–1. In the next round he came close to beating top seed Zhou Yuelong, but lost 6–5. He finished the season ranked 77.