Six began his playing career at Division 2 side
Valenciennes, making his debut at the age of 17 in 1972. He helped
Les Athéniens achieve promotion to the top flight in 1975, which was followed by a remarkable season where they finished tenth, and Six finished as the top scorer at the club with 12 goals. After turning down offers from Ajax, Borussia Dortmund and Feyenoord, Six decided to join
Lens in 1977, where he spent a single season, notably scoring a hattrick against
Lazio in the
UEFA Cup. Lens were relegated at the end of 1977-78 and Six would be made the scapegoat. This was followed by two more disappointing years playing for
Marseille, after which his career would become nomadic in the years that followed, playing in Belgium, Germany, England and Turkey.
On 6 October 1984, the 30-year-old made his
Aston Villa debut under
Graham Turner in a 3-0 home win over previously unbeaten
Manchester United. He acquired
Turkish citizenship in order to play as a domestic player at Galatasaray, playing under the name
Dündar Siz. There he won the
Turkish First League championship in 1987–88 season. He ended his career in 1992 after a two-year spell in the newly re-unified 2.Bundesliga with VfB Leipzig. == International career ==