Intentional tennis shirking?

Growing up, I found tennis a bit difficult to watch, and felt it was heading down the path of becoming more and more trying to watch as I got older. Racquets were becoming large and increasingly powerful-- great for the average weekend player, but for the elite it seemed to reduce the length of rallies. (Are there any statistics to confirm/refute this?) Further, those that had the most success seemed to be those that could utilize the technological characteristics of the racquet best. However, in recent years, it seems that technology has yielded to strategy and all-around performance, and those that play a fuller, more fan-friendly game seem to have the most success. The numbers could well bear my assertion out to be wrong; I don't have any statistical proof one way or the other.

Clearly, this comes on the heels of yesterday's epic men's final at Wimbledon. However, I was struck by something else over the weekend. During the women's final, Venus Williams squared off against her sister, Serena Williams, and lost in straight sets. But I noticed a curious thing happening during particularly crucial points on Venus' serves during the match-- she'd throw a poor toss in the air for her serve, and grab the ball on the way down. There's no penalty for this-- she simply throws the ball up again a moment later and serves it.

There are two questions here. First, was it actually happening? That's a numbers issue. Are there any incongruities in her poor tosses? Are they evenly distributed across matches and within matches? I don't have the data; the issue could be put to rest right there...or could be rather interesting...

...because, second, even if the numbers bore it out, was it intentional? Realize that tennis serves, even in the women's game, are in excess of 100 mph and require a significant degree of concentration and timing to return. This means that there's an advantage to be had in disrupting the returner. However, if a spike in faulty tosses increased during more pressure packed moments, it could also mean that the server simply got nervous and failed in the heat of the moment. So that's the pair of situations, if the numbers bear it out-- and given the repetitious nature of serving in tennis, I'd find it a more difficult argument to make that the pressure played an uninteded role on the server.

(A third question, of course, is if the failed tosses do actually have an adverse effect on the opponent.)

I have no idea who to even ask if mis-tosses on serves are tracked...but for a professional tennis player, there sure seemed to be a lot of poor tosses. And at pretty opportune times as well.