During his initial run, Jennings secured a consecutive 74 wins, setting the record as the highest-earning American game show contestant and bringing significant media attention and viewership.

Afterwards, Jennings pursued a career as an author, writing about his experience and exploring American trivia history and culture in a series of best-selling books.

His original appearance on the program marks the longest winning streak, and he also holds the record for the highest average correct responses per game.

He is a member of the Church of Jesus Christ of Latter-day Saints,[8] and spent two years as a volunteer missionary, serving in Madrid, Spain.

[9] He also played on the school's quizbowl team, at one point serving as captain, and graduated in 2000 with a double major in English and computer science.

[3][10] After college, Jennings lived in Salt Lake City and was a software engineer for CHG Healthcare Services, a healthcare-placement firm in Holladay, Utah.

[14] After this rule change, and until Jennings's run, the record winning streak was set by Tom Walsh, who won $186,900 in eight games in January 2004.

The audience gave a standing ovation in honor of both contestants, and Alex Trebek called Zerg a "giant killer" as Jennings embraced her.

On December 1, 2004, the day after his defeat, Jennings made a guest appearance at the start of the broadcast, during which host Alex Trebek acknowledged his success and enumerated the various game show records he had broken.

[33] At the end of the decade, Entertainment Weekly put his run on its "best of" list: "Answer: A software engineer from Utah, he dominated the quizfest for a record 74 shows in 2004, amassing $2,520,700.

[16] In his book Brainiac, Jennings says that the consistency of the original manager's timing had given an increasing advantage to continuing players, and that the change made a noticeable difference in the second season that he was on the show.

Jennings won the $500,000 prize for second place, but as a result of the Ultimate Tournament, Rutter temporarily displaced him as the highest overall winner of money on game shows.

He returned for the 2011 Jeopardy's "IBM Challenge", which featured the company's Watson against Jennings and Rutter in two matches played over three days, the first man-versus-machine competition in the show's history.

College Champion Monica Thieu (who coincidentally eliminated Jennings in a 2016 episode of 500 Questions) to complete his three-person "Team Ken.

Jennings won the championship to be crowned with the "Greatest of All Time" title and a first-place prize of $1,000,000,[41] bringing his lifetime Jeopardy!-related winnings to $3,522,700.

[46] The rehearsal was scheduled for November 8, 2020, but was subsequently cancelled when Schmidt gave the staff the news that Trebek had died that day from his cancer.

[53] Later, The Wall Street Journal reported Jennings was indeed intended to be sole host, but controversy over his remarks on social media hurt his standing, with poor ratings from focus groups and Sony executives fearing his selection could cause backlash.

"[71] After his initial success on Jeopardy!, Jennings secured a book deal,[23] and left his career as a programmer to pursue his original love of writing.

After 800 quizzes, as of November 16, 2021, due to an ever-increasing amount of commitments related to Jeopardy!, book tours, and simply starting to run out of material for the seventh question, Jennings decided to discontinue the email.

[21] In 2005 and 2006, he engaged in several endorsements, including a deal with Microsoft to promote its Encarta encyclopedia software, and Cingular Wireless (now AT&T) featured Jennings in commercials portraying him as having lots of "friends and family" (coming out of the woodwork once he began winning on Jeopardy!).

[93] According to Variety, Jennings was slated to host a new game show for Comedy Central set to premiere in 2005 or 2006, but the project later stalled in development.

in 2008[103] held the possibility of exceeding Brad Rutter's total game show winnings, had Jennings decided to risk the million dollar question.

Jennings appeared on Millionaire in 2014 as a contestant during Guinness World Records Edition themed week, where he won $100,000 after deciding to walk away on his $250,000 question.

[109] In May 2023, he competed against Mayim Bialik and Vanna White on an episode of Celebrity Wheel of Fortune,[110] winning $72,800 for the Equal Justice Initiative.

On September 7, 2017, HowStuffWorks unveiled a new show entitled Omnibus, co-hosted by Jennings and John Roderick, frontman of the indie-rock band The Long Winters.

's IBM Challenge (2011), when he lost to the Watson computer but became the first person to beat third-place finisher Brad Rutter; a $100,000 second-place prize in the Jeopardy!

[122] On November 10, 2015, Jennings was criticized when he tweeted a joke about the death of Daniel Fleetwood, a lifelong Star Wars fan who died of cancer.

When she tweeted about her son's love for the 1980s television character ALF, Jennings responded with "This awful MAGA grandma is my favorite person on Twitter.

[129][130][131] The incident caused controversial past tweets to resurface in which Roderick made comments that were seen as using anti-semitic, homophobic, racist, and other derogatory language.

[135][136] Jennings was reportedly brought in as the host for filming "as a result of Bialik's decision"; some assumed this meant he had crossed the Writers Guild of America West picket line,[137] but a rep from SAG-AFTRA clarified that since Jeopardy!