It is no exaggeration to say that Serena Williams’ season this year has been nothing short of phenomenal. With three Grand Slam titles under her belt and the much hyped “Serena Slam” completed at Wimbledon, it is a year that will go down in history as one of the greatest tennis seasons of all time. 

Win-Loss Record

Williams’ win-loss record for the season was truly outstanding. Serena finished the year with 53 wins and just three losses. That is an an incredible  winning percentage of 94.64 percent. It stands just behind Serena's 2013 season where she won 95.12 percent of her matches with a ridiculous 78-4 record.

High Points

Throughout the season, there were many memorable titles for Williams. The three of course that stand out the most are her wins at the Australian Open, French Open and Wimbledon. With her win at the Australian Open, Williams moved ahead of Chris Evert and Martina Navratilova for second most Grand Slam titles all-time with 19. That trails only Steffi Graf who holds 22 career Slam wins. Her triumph at the French Open was perhaps the hardest fought slam of her three from the season. Five of her seven matches went the full three sets thanks to slow starts and some sloppy play from Williams. However, her struggles perhaps sweetened the finals victory as they demonstrated her ability to win even when she was not playing at her best.

Having won the previous three slams in succession prior to Wimbledon, Williams had the chance to complete the second “Serena Slam” of her career. The hype and media pressure on Williams was huge. The title was won more easily than her French Open victory, but she did have to survive some close calls. She was just two points from defeat in her third round match against Great Britain's Heather Watson before rallying for a win. She was also pushed to three sets by nemesis Victoria Azarenka in the quarter-finals and Garbiñe Muguruza in the final.

Low Points

Losses aside, the main low points of the season for Williams were the injuries she struggled with throughout the year. She had to fight various woes, culminating with her loss to Roberta Vinci in the semi-finals of the US Open, The American was denied her fourth Grand Slam title of the year with that result. Williams said afterwards that she had been struggling with an injury for a while, “It’s no secret I’ve played injured most of the year — whether it was my elbow, my knee, or, in the final moments after a certain match in Flushing, my heart.”

The loss ended Williams’ season as she withdrew from both the China Open and WTA Finals due to knee injuries that she had been struggling with all year.

Best Results

Clearly the best results Williams accumulated across the season were her three Grand Slam wins. She did however prove herself versatile as always in winning other titles along the way. She won her eighth Miami Open crown in April and followed it up later in the year with her 22nd WTA Premier title at the Western and Southern Open during the American hard court swing.

Worst Results

Losing only three times within a season doesn't’t provide much room for critique, however the clear low point of the year was what turned out to be her final match of 2015. When Williams reached the semi-finals of the U.S. Open, she was only four sets from becoming the first player since Steffi Graf in 1988 to win all four Grand Slams in a calendar year. She lost to first time Grand Slam semi-finalist Vinci of Italy and ended the season with 21 career Grand Slams. That ranks her just behind Graf on the all-time list.

Season Grade: A+

No matter how much the title at Flushing Meadows would have meant for her season and career, Serena's season was simply outstanding regardless. Three Grand Slams, completing the “Serena Slam” and having almost a 95 percent winning percentage for the year warrants nothing but the highest grade.