This dress sense coupled with his crowd-pleasing onstage activity (such as dancing to the interval music) saw him become one of the most popular players on the circuit.

He has always seemed to suffer from what Sid Waddell called the "Mardle Drift", which sees his Darts continually land in 5 and Treble 5 instead of the 20/Treble 20.

In 2007, Mardle was beaten in the opening round of the World Championship by unseeded Alan Caves,[3] and subsequently failed to reach the latter stages of a single event that year.

He found his form at the 2008 World Championship, and in a big upset he beat then-13-time champion Phil Taylor 5–4 in the quarter-finals, a match in which he had trailed 3–0.

[4] In January 2008 Mardle was confirmed as the Sky Sports wildcard entry to the 2008 Premier League following his impressive performance at the World Championships.

Whilst this decision was questioned by some, Mardle proved the doubters wrong with a steady campaign which saw him finish in fifth place, missing out on the Play-Offs by just two legs to Adrian Lewis.

[5] At the 2009 Premier League, Mardle amassed only four points from his opening nine games, then missed week ten due to a virus.

[10] Mardle made his final World Championship appearance in 2010, losing 3–0 to Jyhan Artut in the first round, averaging only 72.

[12] He continued his commentary career in the 2012 PDC World Darts Championship, where he co-commentated on every night of the televised event.

[13] On 15 December 2024, shortly before the start of the 2025 PDC World Darts Championship, it was announced that his wife Donna had died earlier in the week at age 52.