1951 - Idea of playing games on TV sets and started

As early as 1951, a young 29-year old TV engineer named Ralph Baer worked at Loral, a TV company. His Chief Engineer, Sam Lackoff, asked him to Build the best television set in the world. Designing a TV set was an easy task for Ralph, and he wanted to add a new concept that his boss did not understand: playing games on the television set. The video game concept was born, but could not be implemented since the boss refused the idea. In September 1966, Ralph came back to his 1951 idea of playing games on TV sets and started building the first video game prototypes. Therefore, Ralph Baer is accordingly credited as the inventor of the video game.

Fonte: Pong Story

1951 - The NIMROD computer was presented at the Festival of Britain

On May 5, 1951, the NIMROD computer was presented at the Festival of Britain. Using a panel of lights for its display, it was designed exclusively to play the game of NIM; this was the first instance of a digital computer designed specifically to play a game.[4] NIMROD could play either the traditional or "reverse" form of the game.

Fonte: Wikipédia