Championship Manager was the very first game in the popular Championship Manager series of association football management simulation games. The game was originally released on the Amiga and Atari ST in September, 1992 and then ported to the PC/DOS platform soon after. The game was written by Paul and Oliver Collyer (the co-founders of Sports Interactive) in their bedroom.
The game featured four playable English divisions (First through to Fourth; the newly-formed FA Premier League did not appear until CM 93/94). Perhaps most notably, each division contained only 20 teams, whereas in real life they contained 22 or 24 teams at that time. Also included were all of the major domestic cups of the time (including the Anglo-Italian Cup) and the 3 major European trophies (including the now defunct Cup Winners' Cup).
Any teams outside of the four playable divisions and all foreign teams had no player names at all. Instead, players were simply called "No.3" or "No.10" depending on which position they played.
One of the most innovative things about the game was the introduction of "average ratings" for players - after each match the performance of every player was graded from 0-10 and as the season went on the player's average rating would allow the manager to easily see how each player was performing.
Source: Wikipedia, "Championship Manager," available under the CC-BY-SA License.