Despite being a six-time champion, a return to Flushing Meadows may bring back bad memories for the 34-year-old, who saw her Grand Slam bid scuppered at the penultimate hurdle 12 months ago when she was on the wrong end of a massive upset, going down to Roberta Vinci at the semi-final stage.
That loss sparked a year-long run without a major title with final losses coming earlier this year to Angelique Kerber in Australia and Garbine Muguruza in France, but Williams put that right at Wimbledon, taking her revenge on Kerber and finally moving alongside Graf.
The fast courts of Flushing Meadows have always been to Williams' advantage and she can make good use of her fearsome serve.
But there are doubts over her fitness coming in with the American having pulled out of the recent event in Cincinnati, citing a shoulder problem which isn't good news for that first delivery.
At her best, Williams is the one to beat but last year showed that when she falters, others are more than capable of taking advantage.