During his time at Ridgewood High School in Ridgewood, New Jersey, he competed on his school's Quiz Bowl team, and attended the National Academic Championship, where he was later named to the Hall of Fame, being one of 19 people named to it in its 25-year history. Madden led his Ridgewood team to consecutive titles at the Eighth & Ninth Annual Omar Q. Beckins Academic Challenge Tournaments, an offshoot of the Westchester Academic Challenge of Knowledge Organization, in 1998 and 1999. He was Omar MVP in 1999, after placing second to Sahir Islam of Somers High School.. David was inducted into the Omar Q. Beckins Hall of Fame in 1999. Madden attended Princeton University, graduating as a Woodrow Wilson School major in 2003. He attended the Free University of Berlin, receiving a Master's Degree in international relations.
''Jeopardy!''
Making his first appearance on the July 5, 2005 episode, Madden continued on a winning streak through September 19, winning a total of nineteen games and $432,400. His last appearance during non-tournament play was on September 19, when he was defeated by Victoria Groce, a musician from Decatur, Georgia. During the 2006 Tournament of Champions, Madden won his first-round match, but failed to win his semifinal match, taking home a consolation prize of $10,000 and bringing his total to $442,400. Madden had first watched Jeopardy! with a babysitter when he was 11–12 years old. Madden would get the correct response to more clues than his babysitter. Madden claims to have studied a great deal in preparation for the show, which helped him with the clues. Madden's parents did not realize he was going to be on Jeopardy! until his first game aired. Madden's streak of 19 wins in regular games was the second-longest in Jeopardy! history. He was later surpassed by Julia Collins and James Holzhauer, and now has the fourth-longest Jeopardy! winning streak. His total winnings in regular games, $432,400, were also the second-highest. He currently has the fourth-highest total winnings after being surpassed by Holzhauer and Jason Zuffranieri. Madden was invited to take part in 2014's Battle of the Decades Jeopardy! event but declined due to contractual issues. He was invited and was able to participate in the 2019 All-Star Games tournament featuring 18 past champions. Madden was selected as the 7th out of 12 picks in the All-Star Games Draft in September 2018, thus becoming a member of "Team Brad", led by the all-time US game show winnings leader, Brad Rutter, along with his former Princeton University Quiz Bowl teammate, Larissa Kelly who was the 6th pick in the draft. Team Brad won their first-round match and in the final episode, airing on March 5, 2019, Team Brad won the All-Star Games Tournament grand prize of $1,000,000, which was split between the three team members. After Madden's share of the prize, his all-time Jeopardy! earnings totaled $775,733.33; he ranks fourth all-time on the show behind Rutter, Jennings, and Holzhauer.
Work as academic competition organizer
In 2010, he founded the National History Bee and Bowl, two academic quiz competitions for students with a history focus. Madden oversees all aspects of NHBB, and has expanded the competitions to include colleges and middle schools in the USA, and high schools in over twenty foreign countries. The competitions outside the USA are known as the International History Bee and Bowl. In 2012, he organized the National History Bee Middle School Competition, whose National Championships were filmed in May 2012 for broadcast on History. Also in 2012, Madden founded the US Geography Olympiad, which serves as the qualifying competition for students in the USA who are looking to attend the International Geography Olympiad. At the 2014 International Geography Olympiad, Madden served as head coach for the American team, which included the overall champion, James Mullen of Cupertino, California. In 2015, Madden founded the International History Olympiad, which brought 111 students from 14 countries together for its inaugural competition, held at the College of William and Mary in Williamsburg, Virginia. In 2016, he founded the United States Academic Bee and Bowl, the National Science Bee, and the National Humanities Bee, all of which are currently directed at students in eighth grade and younger. The inaugural National Championships for all of these events was held in Arlington, Virginia, in May 2016. In 2017, Madden founded the International Geography Bee as a worldwide geography quiz competition. The inaugural IGB World Championships were held in 2018 in Berlin in conjunction with the 3rd International History Olympiad.
