James Spencer "Jim" Courier, Jr. (born August 17, 1970) is a former World No. 1 professional tennis player from the United States. During his career, he won four Grand Slam singles titles, two at the French Open and two at the Australian Open. He holds the record for being the youngest man to have reached the finals of all four Grand Slam singles tournaments, at the age of 22 years and 11 months. He also won five Masters 1000 series titles. Courier is known for having an extensive knowledge of tennis rackets and strings. As of 2013, Courier is the last man to win the Australian Open and French Open back-to-back, in 1992.