Question: What sport did a German father and son duo both play?

full_context: Document 1: Bastian Schweinsteiger: Bastian Schweinsteiger (] ; born 1 August 1984) is a German professional footballer who plays as a midfielder for Major League Soccer club Chicago Fire. A right-footed player, he usually plays as central midfielder. Earlier in his career, he primarily played as a wide midfielder.
Document 2: Jiří Zídek Sr.: Jiří Zídek Sr. (born February 8, 1944) is a retired Czech basketball player. At 6'9" (2.06 m), Zídek was a talented center, and is considered by many to arguably be the best Czech basketball player ever. He was named the Best Czech Player of the 20th Century. He was among the 105 player nominee list for the 50 Greatest Euroleague Contributors list. His son, Jiri Zidek Jr., won the Euroleague title with Žalgiris in 1999. They are to this day, the only father and son to have reached a Euroleague title game as players.
Document 3: Ralf Zumdick: Ralf Zumdick (born 10 May 1958) is a former German football goalkeeper. After his career (21 2. Bundesliga, 282 Bundesliga games; one goal) Zumdick was assistant coach at VfL Bochum from 1995 till 1999. Zumdick is often cited as the player who pioneered the practice of the penalty-taking-goalkeeper when he scored against Andreas Köpke in 1988. He is currently manager Thomas Doll's assistant coach at Ferencváros.
Document 4: Dino Zoff: Dino Zoff (] ; born 28 February 1942) is a former Italian professional football goalkeeper and is the oldest winner ever of the World Cup, which he earned as captain of the Italian national team in the 1982 tournament in Spain, at the age of 40 years, 4 months and 13 days, also winning the award for best goalkeeper of the tournament, and being elected to the team of the tournament, for his performances, keeping two clean-sheets, an honour he also received after winning the 1968 European Championship on home soil; he is the only Italian player to have won both the World Cup and the European Championship. Zoff also achieved great club success with Juventus, winning 6 Serie A titles, 2 Coppa Italia titles, and an UEFA Cup, also reaching two European Champions' Cup finals in the 1972–73 and 1982–83 seasons, as well as finishing second in the 1973 Intercontinental Cup final.
Document 5: Heinz Ditgens: Heinz Ditgens (3 July 1914 – 20 June 1998) was a German professional footballer who played club football for Borussia Mönchengladbach. He won three caps for the German national side between 1936 and 1938, participating at the 1936 Summer Olympics, and became Borussia Mönchengladbach's first ever international player in the process. Ditgens also fought at Stalingrad in World War II.
Document 6: Djalma Dias: Djalma Pereira Dias Júnior (21 August 1939 – 1 May 1990) was a Brazilian footballer who played as a defender.
Document 7: Zoltán Czibor: Zoltán Czibor (23 August 1929 – 1 September 1997) was a Hungarian footballer who played for several Hungarian clubs, including Ferencváros TC and Honvéd, and Hungary before joining CF Barcelona. Czibor played as a left-winger or striker and was notable for having a powerful shot, good pace and excellent ball control. During the 1950s he was part of the "Magical Magyars". After the 1956 Hungarian Revolution he moved to Spain where he became a prominent member of the successful FC Barcelona team of the late 1950s. After three seasons at Barcelona, he joined their local rivals Español for the 1961/62 season. After brief spells at FC Basel, FK Austria Wien and Primo Hamilton FC, he retired as a professional footballer and returned to Hungary. He died there in 1997, aged 68.
Document 8: Sokratis Papastathopoulos: Sokratis Papastathopoulos (Greek: Σωκράτης Παπασταθόπουλος , ] ; born 9 June 1988) is a Greek footballer who plays as a starting centre back for German Bundesliga club Borussia Dortmund and the Greek national team. Since the surname Papastathopoulos is too long to print on the back of most shirts, the name Sokratis is usually displayed and is the singular name that he is best known by in the football world.
Document 9: Sándor Kocsis: Sándor Péter Kocsis (] ; 21 September 1929 – 22 July 1979) was a Hungarian footballer who played for Ferencváros TC, Budapest Honvéd, Young Fellows Zürich, FC Barcelona and Hungary as a striker. During the 1950s, along with Ferenc Puskás, Zoltán Czibor, József Bozsik and Nándor Hidegkuti, he was a member of the "Mighty Magyars". After the 1956 Hungarian Revolution he moved to Spain where he became a member of the FC Barcelona team of the late 1950s.
Document 10: Michael Zorc: Michael Zorc (born 25 August 1962) is a German retired footballer who played as a central midfielder.
Document 11: Zé Roberto: José Roberto da Silva Júnior (born 6 July 1974), commonly known as Zé Roberto, is a Brazilian professional footballer who plays for Palmeiras as a left wing back or as a midfielder.
Document 12: Michael Ballack: Michael Ballack (] ; born 26 September 1976) is a retired German footballer. He is among the top goal scorers in the history of the German national team. Ballack wore the number 13 shirt for every team he has played for, save for 1. FC Kaiserslautern. He was selected by Pelé as one of FIFA's 125 Greatest Living Players, and as the UEFA Club Midfielder of the Year in 2002. He won the German Footballer of the Year award three times – in 2002, 2003 and 2005. Ballack was known for his passing range, powerful shot, physical strength and commanding presence in midfield.
Document 13: Dieter Zorc: Dieter Zorc (born 17 October 1939 – 16 October 2007) was a German football defender. He was the father of Michael Zorc.
Document 14: Thomas Müller: Thomas Müller (] ; born 13 September 1989) is a German professional footballer who plays for and vice-captains Bayern Munich and the German national team. A versatile player, Müller plays as a midfielder or forward, and has been deployed in a variety of attacking roles – as an attacking midfielder, second striker, centre forward and on either wing. He has been praised for his positioning, teamwork and stamina, work-rate, and has shown consistency in both scoring and creating goals.
Document 15: Mario Götze: Mario Götze (] ; born 3 June 1992) is a German professional footballer who plays as an attacking midfielder for German Bundesliga club Borussia Dortmund and the Germany national team. Although his favoured position is that of a playmaker. Götze possesses speed, technique, dribbling skills, and playmaking capabilities. In 2010, German Football Association's then technical director Matthias Sammer described Götze as "one of the best talents Germany has ever had."
ground_truth: football