The video game console market started in 1972 with the release of the first home console, the Magnavox Odyssey. As more manufacturers entered the market and technology improvements, the market began to coalesce around the concept of console generations, groupings of consoles with similar technical specifications that vied in the consumer marketplace. Since 1972, there have been nine such console generations, with two to three dominant manufacturers controlling the marketplace as an oligarchy.[1]