The Power Index is the average maximum hitting speed of any player as judged by maximum: a) 1st Serve Speed; b) 2nd Serve Speed; c) Forehand; d) Backhand; e) 1st Serve Return; f) 2nd Serve Return; and g) Smash.
*Only calculates players appearing on center court.
it's been updated folks
1 Shvedova, Yaroslava (RUS) 102.9 MPH
2 Petrova, Nadia (RUS) 97.4 MPH
3 Ivanovic, Ana (SRB) 95.6 MPH
4 Shaughnessy, Meghann (USA) 94.7 MPH
5 Azarenka, Victoria (BLR) 93.9 MPH
6 Mirza, Sania (IND) 93.8 MPH
7 Kirilenko, Maria (RUS) 93.5 MPH
8 Peng, Shuai (CHN) 93.3 MPH
9 Dementieva, Elena (RUS) 92.1 MPH
10 Sharapova, Maria (RUS) 91.0 MPH