Here is a Tennis.com article about it.
please read it at the following link:
Excerpts about Martina Hingis...
6. Martina Hingis – Effectively tied with Clijsters and has the chance to overtake her if she can put up some good results – losing her second match in Seoul this week was an opportunity lost. Historically, she likes indoor surfaces a lot, though she hasn't played indoors much in her comeback.