Originally Posted by domon17th
I don't think it's all that. For eg, I'm sure she has many more aces and a higher 1st AND 2nd serve winning % during the US Summer HC and fall 2006. It's not always the speed, she used to have incredible serve placement.
She probably did have higher winning %s on 1st and 2nd serve back then, BUT that isn't necessarily due to the serve, those stats are affected by the rest of your game. (For instance, Azarenka has one of the highest % of points won on her 2nd serve this year; the puffball 2nd serves she puts in are obviously not even close to being among the best, but it's because she backs it up with the rest of her game being so solid.)
In terms of aces and unreturned serves, Maria is pretty close to the level she was at in 2006. She definitely puts the same amount of raw pace on it as she ever did, I agree she's maybe lost a bit of variety in placement, but overall her serve has been close to its peak since the start of 2012. But she's never going to have a serve that does all
the work for her if the rest of her game isn't up to the required standard; look at Venus, she still had comfortably the 2nd-best serve on the WTA until a couple of years ago yet she still couldn't win shit away from grass.