Concentration(1958)

Concentration is an American game show that ran on and off from 1958 to 1991, built around a memory card-matching mechanic. Contestants flipped cards to find matching pairs, which revealed pieces of a rebus puzzle they had to solve to win each round. The original NBC daytime series became the network's longest-running game show, airing for over 14 years with 3,770 episodes. Hosted by Hugh Downs and later Bob Clayton—with Ed McMahon taking the helm for six months in 1969—the show moved through several time slots before settling at 10:30 AM. Most episodes were produced at NBC's New York headquarters. Concentration also spawned a weekly nighttime version that aired in two separate runs: a brief October-November 1958 stint hosted by Jack Barry, and a longer April-September 1961 run with Downs returning to host.