At her best, she moves like a Rolls Royce, smooth and efficient, soaking up the pace of her opponents with ease and sending it back with interest.
At the other end of the scale, she’s lost in the first round at a Grand Slam 12 times, sometimes looking demotivated.
Though she won the title in Guadalajara in February, she touched down in Paris this year having lost in the first round in four straight clay-court tournaments, lacking confidence.
And yet, despite arriving with no form whatsoever, she has now strung together three strong performances in Paris to reach the last 16, where on Sunday she meets Jil Teichmann of Switzerland for a place in the quarter-finals.
“Considering that I did not win a single match before coming into the French Open, I would say that I'm doing the absolute best that I can and that I am pleased to be in the fourth round for the eighth time,” said the 29-year-old, who is a former world No.3 but is down to No.64 in the rankings.