Has anyone discovered the essence of Federer that makes him such a near-invincible threat? His ground strokes are technically sound, [not to mention easy on the eye] he serves very well, in that, he can hit bombs all day but more often than not chooses to place it divinely on the lines, his transition game is superb and plays defense very well especially by utilizing his effective backhand slice, his footwork and movement is impeccable and so he covers the court expertly, volleys very well, though I wouldn't venture to label him as the best pure volleyer in the game [Pat Rafter comes to mind] and I would say that's probably because he relies more on his more than adequate baseline game, and of course he's very stable mentally. If I had to guess I would say that Federer's mental game, because it's so strong and it should be, is the bigger factor, even over his strokes and defense, that put's Federer above the rest. As the saying goes, tennis is 75% mental. Agree? Disagree? I'm open to all opinions and feedback.