I had three handheld electronic games in the late 1970s.
The Mattel Football Game allowed you to score touchdowns and kick field goals against the opposing team. If you figured out the pattern for the opposing team, you can score 100 points to zero points for every game.
You couldn’t beat the Mattel Battlestar Galactica Space Alert. The game ended only when a Cylon Raider reaches the bottom of the screen to destroy the Galactica. Each wave of 20 Cylon Raiders kept coming down the screen in the same predictable pattern. That pattern allowed me to play the game for a very long time.
The Coleco Quiz Wiz was a bit different. The “computer” plugs into a cartridge with a booklet that had 1,001 trivia questions. Since I memorized the 1,001 answers for the first cartridge, I had the answers for the second and third cartridges. I gave up on buying any more cartridges after I discovered that pattern.
NOTE: Check out the longer version of this blog post.