premise: Sebastian Vettel was a racecar driver in Formula One.
hypothesis: Sebastian Vettel ( [ zeˈbasti̯an ˈfɛtl̩ ] ; born 3 July 1987 ) is a German racing driver currently driving in Formula One for Scuderia Ferrari . He is a four-time Formula One World Champion , having won the championship in , , and with Red Bull Racing . He is contracted to remain as a Formula One driver with Scuderia Ferrari until at least the end of 2017 . Vettel started his career in Formula One as a test driver for BMW Sauber and made his debut with the team at the 2007 United States Grand Prix , replacing the injured Robert Kubica . He followed up his first championship with three more titles , becoming the youngest double , triple and quadruple world champion in Formula One .