Australian Open contenders deliver vastly different degrees of tennis

With the quarterfinals half finished, we have already seen our share of surprises, though we have not seen that much good tennis. Recognition has to go to:

Tszvetana Pironkova, who held her nerve and knocked Venus Williams out of round one

Daniela Hantuchova, who, showing much of her old form, dispensed of Venus's sister in the third round

Maria Kirilenko, whose level of competitive play against world number one Lindsay Davenport was tough, creative, and almost successful

Samantha Stosur, who lost her nerve against an almost equally nervous Martina Hingis, but who proved why her fans yell, "Smash-em Sam!", winning beautiful points at the net over and over. Once thought of as a doubles-only player, Stosur is coming into her own in singles.

Amelie Mauresmo, who--given her sometimes fragile psyche--could have let the talented young Nicole Vaidisova scare her, but chose instead to dispense of Vaidisova cleanly and with authority

Lindsay Davenport, who played through a freak ankle injury which all but destroyed her ability to serve, but which didn't put her on the wrong side of the handshake until she met up with Justine Henin-Hardenne in the quarterfinals

Ashley Harkleroad, whose very slow return to professional tennis got her through two qualifying rounds and past the talented Shaui Peng. It was her tough luck to meet Sharapova in the second round, but she played very well against her and should be proud of her performance.

Martina Hingis, whose match statistics are incredible, and who is playing the same terrific game she always played, but with more power and more trips to the net

And another kind of recognition should go to:

Serena Williams, who insists she's just fine, thank you, but who is out of shape and not a threat to anyone at the top of the tour

Maria Sharapova, who bragged to the press about how she could defeat Nadia Petrova under any circumstance (and making excuses for her loss to Petrova at the Year End Championships), and then proceeded to play an absolutely horrible match against Petrova in the quarterfinals. Making unforced errors repeatedly and double-faulting again and again, Sharapova was completely out of form. Of course, the commentators acted, as they always do, as though this were the very first time Sharapova had ever done something like this.

Nadia Petrova, who did manage to do something difficult: She played even worse than Sharapova. Petrova made 49 unforced errors in two sets, couldn't stop double-faulting, and let the old temper-prone Nadia rule her terrible game. (In all fairness, however, she played part of the match with bleeding blisters and had to have the trainer come in twice.)

Iveta Benesova, who has a fine game (she defeated Mary Pierce), but whose training at the Nadia Petrova School of Emotional Control made her easy pickings for Martina Hingis