Roger Federer and other great champions have often talked about the pressures of playing when you are always expected to win and your opponents have nothing to lose and often go for broke.  As one watched Serena Williams struggle to barely defeat fast-rising Israeli, Shahar Peer, one could feel all those complicated emotions in Serena's uneven play.  Serena's serve pulled her through a lot at times as it has often at this Australian Open, but her baseline, especially her forehand, seemed to feel the pressure the most.  Serena has talked about sort of having nowhere to go, but up in the rankings this year.  However, she also clearly feels the pressures of having a "good draw" to the finals.  There's a fine line between "playing to win" and playing "not to lose."  At their best, great champions are somehow able to pull out their best tennis when it really matters by going for their shots rather than giving away points with errors or waiting for their opponents to miss.  Serena has shown a little of all of the above in her Australian Open matches so far and it would be fascinating to see what it would mean for her confidence if she could somehow break through and actually win the 2007 Australian Open title.  My guess is that it would keep her around the very top of tennis for at least a couple more years... but we'll see...