Serena Williams was named WTA Tour player of the year for the fourth time on Thursday following a remarkable 2012 season. The 31-year-old American has been by far the standout player despite a slow start to the year where she was beaten in the fourth round of the Australian Open. But the 15-time Grand Slam winner was virtually unstoppable from April to October when she won 48 of her 50 matches. She claimed seven singles titles during this period including the US open and Wimbledon crowns. She also won Olympic gold in the singles to complete a Career Golden Slam, becoming only the second woman to do so, after Steffi Graf. She was victorious in the Olympic doubles with sister Venus and finished off the year by winning season-ending WTA Championships in Istanbul. It’s the fourth time the world number three has won the award – voted for by the international tennis media – after 2002, 2008 and 2009.