Mattel Electronics' team of programmers was diverse in experience and talent, which proved to be an advantage. As competitors often depended on licensing well known trademarks to sell video games, Mattel focused on original ideas. Don Daglow was a key early programmer at Mattel and became director of Intellivision game development. Daglow created "Utopia", a precursor to the sim genre and, with Eddie Dombrower, the ground breaking sports simulation "World Series Major League Baseball". Daglow was also involved with the popular Intellivision games "Tron Deadly Discs" and "Shark! Shark!". After Mattel Electronics closed in 1984, their programmers continued to make significant contributions to the videogame industry. Don Daglow and Eddie Dombrower went on to Electronic Arts to create "Earl Weaver Baseball", and Don Daglow founded Stormfront Studios. Bill Fisher, Steve Roney and Mike Breen founded Quicksilver Software and David Warhol founded Realtime Associates.