Began playing tennis at age six...Father, Rainer, is an English and History teacher while his mother, Henriette, is a council employee...Has one older sister, Gwendolyn, who is also a teacher (born in 1975)...Both parents played tennis for fun...Lists his parents and Boris Becker as inspiration for playing tennis...Grew up playing in the First Line Tennis Academy in Stuttgart for over 15 years and still trains there...Favorites surfaces are hard and clay courts...After completing his last year of school, was required to complete 10 months of compulsory Army service but only served two, as elite athletes receive eight months exemption...A big fan of Dallas Mavericks and countryman Dirk Nowitzki and follows Stuttgart in German Bundesliega (soccer)...Says if he wasn't a tennis player he would be a soccer player.