Ratings for “Jeopardy!,” which had been on a ratings tear as contestant Ken Jennings enjoyed a dramatic winning streak, plummeted once the show went into repeats, according to Nielsen Media Research data for the week ending Aug. 1.

The game show’s winning streak-which pushed the show to the syndicated top spot for the previous two weeks-mirrored that of Mr. Jennings, whose domination of the game began in late June. Mr. Jennings has yet to lose and is scheduled to return when new episodes begin.

But without the suspense of seeing whether Mr. Jennings could survive another game, King World-distributed “Jeopardy!” failed to retain any residual audience from its previous heights, dropping 38 percent, from a 9.6 national household rating to a 6.0-its second-worst week this season. The performance was, however, even with the same week last year, when the show also registered 6.0.

King World stablemate “Wheel of Fortune,” which airs after “Jeopardy!” in many markets, fell 14 percent to 7.3. But due to the collapse of “Jeopardy,” “Wheel” regained the top syndie position.

Other game shows also suffered, including Buena Vista Television’s “Who Wants to Be a Millionaire” (down 5 percent to 3.6) Sony Pictures TV’s “Pyramid” (down 11 percent to 1.7) and King World’s “Hollywood Squares” (down 17 percent to 1.5). Their drops may have been collateral damage from drought of “Jeopardy!”-driven viewers. Viewers may also have been drawn to cable news coverage of the Democratic National Convention. Tribune Entertainment-distributed “Family Feud” was the only game show to increase, up 5 percent to 2.2.

Among talk shows, performance was mixed. King World-distributed “Dr. Phil” was up 5 percent to 4.0, NBC Universal’s “Maury” was up 3 percent to 3.0 and Paramount Domestic Television’s “Montel Williams” was up 4 percent to 2.4. But King World’s “The Oprah Winfrey Show” was down 8 percent to 5.6 and Buena Vista’s “Live With Regis and Kelly” was down 3 percent to 3.3.