Jack Sock has made quite a splash in the tennis world over the past two years. In 2010, he won the USTA Boys’ 18s National Championships and the US Open boys’ singles title, becoming the first American US Open boys’ champion since Andy Roddick in 2000 and the first to win both championships in the same year since Brian Dunn in 1992. In 2011, Sock repeated as the USTA Boys’ 18s champion, became the first USTA Boys’ 18s winner also to win a round in the main draw of the US Open in 15 years, and claimed his second US Open title in two years, this time in mixed doubles with Melanie Oudin. For good measure, he won his fourth Kansas state high school title in four years and finished his high school career undefeated. On the USTA Pro Circuit, Sock reached three doubles and one singles final in 2011, with a doubles title at the Futures in Palm Coast, Fla.