^I think you're right, Sam often plays really well when she lets rip with a few choice words. But I think it's because she doesn't do it very often that it works so well. It means something when she does it. I while ago Fed remarked on all the come-ons, fist-pumps and such that most of WTA players seem to do after just about every single point. His point was that if you do it all the time it doesn't really have any effect, it's just another silly habit that you can't do without. If you do it on really key points it can really help though, because those are the points where you really need to be pumped up.
I don't know whether Sam has thought it through like this, but she seems to follow Fed's rule pretty well, maybe intuitively. When Sam swears, pumps her fist or (my favorite) gives herself that cute little buttslap, it really seems to help her focus and get her energy channelled in the right direction.
To me, the buttslap is kind of a habit. It's part of her little ritual before a point. Like blowing on her fingers. Allowing herself a good fist pump is her way of acknowledging that she made a good shot, feeling the enjoyment of it, and channeling the motivation for the next one. Ah, but the swearing....I think she needs this outlet for her frustration and anger. Sure, I joke about wanting to see it more, but I'm glad she doesn't overuse it. I'm just happy when she does swear because it means she is expressing that bad feeling and not carrying it around with her into the next point.
It's important for her to feel her emotion, acknowledge it, then move on from it and get back into the present without it becoming a spectacle like some of the others
. I agree those gestures and things are overused on the WTA - and if we wanted to analyze it, I'm sure we could trace it back to some sports psychologist who planted a seed somewhere in the players' heads that they need a way to pat themselves on the back for good points, or even mediocre ones. Lucky for us, we have a fave who has adorable ritual habits - finger blowing, buttslap, moderate use of fistpump, and the occasional FUCK!!!