The WTA had a power index for the first four events of 2009.
The Power Index is the average maximum hitting speed of any player 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.
2009 CUMULATIVE AFTER FOUR EVENTS
1 Samantha Stosur (AUS) 100.01 MPH
2 Jelena Dokic (AUS) 94.88 MPH
3 Serena Williams (USA) 94.67 MPH
4 Ana Ivanovic (SRB) 92.94 MPH
5 Tamira Paszek (AUT) 92.84 MPH
6 Nadia Petrova (RUS) 92.6 MPH
7 Dinara Safina (RUS) 92.31 MPH
8 Venus Williams (USA) 92.04 MPH
9 Svetlana Kuznetsova (RUS) 91.64 MPH
10 Gisela Dulko (ARG) 90.74 MPH
Gael Monfils has the Fastest Forehand ever clocked at 118.1 mph or 190 km/h, against Marcos Baghdatis at the 2007 Australian Open. Although it has been noted by many that Andre Agassi who yields, arguably, the greatest forehand ever, has hit with considerably more "pace" than Gaël Monfils but was never "clocked" at the appropriate occurrences due to the lack of technological advancement in tennis during Andre's more "prime years" (From:http://www.absoluteastronomy.com/topics/Forehand