Affectionately known as the "Aliens", four riders have typically dominated MotoGP for roughly a decade. Until his retirement after the 2012 season, Casey Stoner was one of those four riders, along with Valentino Rossi, Jorge Lorenzo and Dani Pedrosa. Stoner was promptly replaced by Marc Marquez when he joined the series in 2013. Nevertheless, the Club has remained very exclusive : only four members.