I'm not sure if this was mentioned, but the very first Super Bowl broadcast was aired on two networks (CBS and NBC, due to it being AFL/NFL), and both of them wiped their tapes! OF course, the NFL filmed the game for their own archives, but the TV telecasts (with play-by-play, etc) doesn't exist in full (a colour videotape of the 1st, 2nd and 4th quarters was discovered a few years ago).
many other early sporting events were wiped or otherwise not retained. Most (but not all) World Series games before 1975 are incomplete.
By the way, in response to my comment on the colour What's My Line CBS episdoes: though a B/W kinescope of a programme made in colour does mean that the episode isn't "completely" missing, the original colour version of the episode is still considered by many (including me) to be "lost" and worth being recovered (I read elsewhere about 3/4 of the colour WML?s were actually recorded onto colour tape first--not live--and also onto B/W film, just that the tapes were later junked).
Actually, a home recording of the CBS broadcast of Super Bowl I on a primitive video tape machine is now confirmed to exist and has been restored by the Museum of TV/Radio. But the NFL has not been able to work out a deal with the original taper to obtain it for marketing purposes.
Years ago I once wrote a letter to Gil Fates, the executive producer and asked why videotapes of WML had not been preserved by Goodson-Todman considering that they did so for the syndicated run of the show and also retained the original B/W videotapes of the nighttime Password show from 1962-1965. He wrote back and said it was a matter of economics because CBS only charged them $10 for a kinescope print and that was more economical from their standpoint. That didn't explain why the Password videotaes survived (Though that show Fates was not involved with). A single nighttime To Tell The Truth hosted by Bud Collyer exists in color videotape format (April 24, 1967) and there are many B/W and color videotapes of the daytime To Tell The Truth from 1965-1968 (along with a year of color daytime Password from 1966-67 but those episodes alas were cut down for syndication in the late 60s prior to the ABC revival). No color tapes of the CBS network version of "I've Got A Secret" are known to exist.
These are the World Series broadcasts that exist.
1952 (Yankees-Dodgers) Games 6 and 7
1955 (Dodgers-Yankees) Game 5 partial
1956 (Yankees-Dodgers) Game 2 (partial), Game 3 (2nd and 3rd innings missing), Game 5 (Larsen's perfect game; missing first inning)
1957 (Braves-Yankees) Game 3 near complete and partial Game 6
1960 (Pirates-Yankees) Game 7, found in Bing Crosby's cellar
1961 (Yankees-Reds) partials of Games 3, 4, 5
1963 (Dodgers-Yankees) Game 3. Has not surfaced in collectors market
1965 (Dodgers-Twins) All 7 games complete from CBC kinescopes
1968 (Tigers-Cardinals) All 7 games complete from CBC kinescope
1969 (Mets-Orioles) Games 1 and 2 B/W kinescopes from CBC; Games 3-4-5 oldest color videotape WS games extant
1970 (Orioles-Reds) Complete. Games 1-4 B/W CBC kinescopes; Game 5 in color tape quality
1971 (Pirates-Orioles) Games 1-2-6-7 complete, Games 3-4-5 partial only. All in color
1972 (A's-Reds) Game 4 only game complete. Game 2 and Game 5 mostly intact to near complete. Partials and fragments only for Games 1-3-6 and NOTHING of Game 7
1973 (A's-Mets) Complete Game 1; Game 2 near complete but missing last inning; Game 3 likewise; Game 4 and Game 5 small partials; Game 6, just small amounts from a Cartridgevision home recording; Game 7 near complete but cuts off in TOp 9th. Last out recovered from Peabody Archives compilation reel.
1974 (A's-Dodgers) All complete except Game 5 missing final inning and first couple innings.