Current world number one has had a less than satisfactory season by her standards. Despite winning tour-leading 5 titles, her early exits in Roland Garros and Wimbledon marred her 2014 campaign. However, like the saying "when the going gets tough, the tough gets going", Serena stepped it up big time in her US Open run-up and salvaged the season with a win in Flushing Meadows. Withdrawing from the China tournaments with injuries, Serena doesn't look to be 100% going into the tournament. But I believe the world number one is dead set on retaining her ranking, and will be hungry to prove her detractors wrong again.
Serena really needs no introduction. She perfected the power game, bullying her opponents around the court with well struck and powerful strokes. Her serve is the best on tour, and can even rival some of her counterparts on the ATP tour. Serena has somewhat evolved her game to introduce more spin, which is great for her game as her younger and raw-er game is more error prone.
Chances of winning Singapore: 95%
After her draw ceremony, Serena went straight to the practice courts, showing how committed she is to perfecting her game before Monday. When she's this serious, she's almost unstoppable. Besides, only Ana has beaten her in her group, so she should emerge safely from the group stages.