Throughout the original show’s run on ABC from 1966 to 1971, a total of 20 episode numbers were used for pre-emptions or were skipped. The following episodes do not and have never existed:
109, 110, 131, 226, 369, 391, 533, 634, 653, 802, 824, 895, 914, 920, 921, 1135, 1155, 1175, 1180, 1208
Numbering system[]
The main reason for skipping certain episode numbers was due to a numbering system that the show used. Each episode was numbered so that it can be easily determined which day of the week any given episode aired simply by looking at the episode’s last number:
- Monday episodes end in a 1 or 6
- Tuesday episodes end in a 2 or 7
- Wednesday episodes end in a 3 or 8
- Thursday episodes end in a 4 or 9
- Friday episodes end in a 5 or 0
Out of sync episodes[]
Occasionally the above described numbering system would go out of sync due to unforeseen events that caused the show to be unexpectedly pre-empted and not shown when it was planned for in the schedules. This would usually be corrected shortly after by double numbering and in one case triple numbering later episodes.
The following is a list of episode numbers that are out of sync along with the reasons why this happened:
- Episode 206 was pre-empted, due to the AFTRA strike. It was originally scheduled for broadcast on April 10, causing the following episode numbers to go out of sync by one day:
- Episode 509 was pre-empted, due to the news of the Robert Kennedy assassination. It was originally scheduled for broadcast on June 6, causing the following episode numbers to go out of sync by one day:
- Episode 818 was pre-empted, due to news coverage of the astronauts in Chicago. It was originally scheduled for broadcast on August 13, causing the following episode numbers to go out of sync by one day:
- Episode 891 was pre-empted, due to news coverage of the Apollo 12 splashdown, causing the following episode numbers to go out of sync by one day:
- Episode 893 was pre-empted, due to the Thanksgiving Day football, causing the following episode numbers to go out of sync by two days:
- Episode 918 was pre-empted due to New Year’s Day, causing the following episode numbers to go out of sync by two days:
- Episode 1130 was pre-empted due to coverage of a speech given by President Nixon to the United Nations, causing the following episode numbers to go out of sync by one day:
Planned pre-emptions and double numbered episodes[]
The following list goes into further detail about the 20 skipped episode numbers and the reasons for this happening:
- 109: Expected pre-emption for a Thanksgiving Day football game.
- 110: Expected pre-emption for the day after Thanksgiving football
- 131: Expected pre-emption for the Christmas Day football game.
- 226: This episode is not a pre-emption. It was double numbered with 225 (225/226) in order to correct the “out of sync” numbering caused by the AFTRA strike.
- 369: Expected pre-emption for the Thanksgiving Day football game.
- 391: Expected pre-emption for Christmas Day.
- 533: This episode is not a pre-emption. It was double numbered with 532 (532/533) in order to correct the “out of sync” numbering caused by news coverage of the Robert Kennedy assassination.
- 634: Expected pre-emption for the Thanksgiving Day football game.
- 653: Expected pre-emption for the Christmas Day basketball game.
- 802: Expected pre-emption by the Apollo 11 Lunar/Command Module docking manoeuvres.
- 824: This episode is not a pre-emption. It was double numbered with 823 (823/824) in order to correct the “out of sync” numbering caused by news coverage of the astronauts in Chicago.
- 895: This episode is not a pre-emption. It was double numbered with 894 (894/895) in order to correct the “out of sync” numbering caused by the Thanksgiving Day football coverage.
- 914: Expected pre-emption for Christmas Day.
- 920 & 921: These episodes are not pre-emptions. They were triple numbered with 919 (919/920/921) in order to correct the “out of sync” numbering caused by news coverage of the Apollo 12 splashdown and New Year’s Day.
- 1135: This episode is not a pre-emption. It was double numbered with 1134 (1134/1135) in order to correct the “out of sync” numbering caused by coverage of a speech given by President Nixon to the United Nations.
- 1155: Expected pre-emption for the Thanksgiving Day basketball game.
- 1175: Expected pre-emption for Christmas Day.
- 1180: Expected pre-emption for New Year’s Day.
- 1208: Expected pre-emption for coverage of the Apollo 14 splashdown.