Palermo, R2: (6)Tsvetana Pironkova def. Sorana CÓrstea 2-6 6-1 6-1
2009 Sorana with more than 50% first serves just lasted for one set, then she switched with slumping Sori again...
It's true that her first serve percentage dropped a little- from 58% in the first set to 44% in the second and 47% in the third, but the real killer was the amount she was winning behind her serves.
In the first set she was winning 74% of her serving points (73% behind first serve, 75% behind second serve) while in the second set she won only 33% of serving points (33% behind both first and second serve). And in the third set she wasn't much better, winning only 47% of serving points (38% behind first serve, 56% behind second serve).
Overall she won less behind her first serve (48%) than behind her second serve (50%). Pironkova was not doing particularly well behind second serve (46%, worse than Sori) but she won a respectable amount behind the first serve (68%).
Naturally, you would also like to get a decent first serve percentage (I always suggest 55-60% as an okay target) but in Sorana's case sometimes she doesn't win points even when she gets the first serve in.
It's hard to tell how much of this is due to the serve itself and how much is due to Sori's poor following-up of the serve. Normally, to win a good amount of points behind the first serve you need to either get free points (not really a wta thing unless you're a way above average server) or at least gain a slight advantage and use the serve to start an attack or stay in charge of a point. Clearly, Sorana is not doing well when she tries to use attacking combinations like the 1-2 punch etc. Without seeing it I think when she loses a bit of rhythm (which happens most of the time nowadays) every time she tries to attack she mistimes the ball.
I would guess that in the first set Pironkova was pretty bad, and Sorana's aggressive shots were going in a litt e more than usual for her these days. Either that or Tsveti was missing a lot of returns and not giving Sori a chance to make errors.