Just eight players left now in each event, so I thought it's a nice time to give an update.
Federer - the obvious favourite, and in awesome form. He just toyed with Hewitt and hasn't lost a set since R1. Best asset is he knows what to do at this end of a tournament.
Davydenko - wobbled against Verdasco, led 2-0 and then had a mini-break in the fourth set breaker, before winning in five sets, having given his backers at 1.05 many grey hairs. Has beaten Federer in their last two clashes, after being 0-12 before November. But how will he go over the best of five sets, and with much more at stake?
Djokovic - a bit wayward against Chiudinelli, but otherwise solid. Record is 2-4 v Tsonga, winning their first clash (AO final 08) and Miami last year. He hit a bit of a flat spot in between, the effects of an overloaded schedule and changing racquet brand - I think he is back close to his peak now.
Tsonga - only scraped through against Almagro, almost throwing away a 2-0 lead. His task has gotten tougher with each round, and I'm not sure there's much left for him to improve here. Will be tough for him to go much further.
Roddick - good win over Gonzalez, but was expected to do so, having a 8-3 record before that contest. Had a twinge of the knee late in the match, not sure if that is anything to worry about, but keep an eye on it tonight. QF/SF is his usual level, needs to play exceptional tennis to reach the final from here.
Cilic - lifted a gear to beat del Potro and I think that win was a major mental hurdle for him to clear. JdP had beaten him in Melbourne and New York last year, so put those losses behind him was a step forward. 1-1 vs Roddick, he can do it. I am on him for the title and happy to let it ride through this match, will worry about trading some of the position off later.
Murray - in fine touch against Isner, no sign of the back twinge in the previous round. Record is 3-7 against Nadal but I'm happy to ignore his last two losses - one on clay and the other at Indian Wells when the wind was ridiculous. He'd won three in a row before that. Can go all the way if at the top of his game.
Nadal -solid without being brilliant so far. His main worry is his recent record against top 10 players. Since losing at the French Open, he has lost ten matches and won only two (Tsonga, Paris Masters, Nov) and Soderling (Abu Dhabi exhibition Dec/Jan) against the top guys. That has to start getting into his head...
I'm still happy with my bets on Federer and Cilic.
Serena W - has only dropped 15 games in four rounds so far, and hasn't been broken once (saved 12 break pts). That's up there with her best, but she's lost here with similar form and has also won the title with scrappy, fighting tennis.
Azarenka - displayed another level of maturity with her win over Zvonareva. I thought she was gone at 4-6 1-3 but she dug deep and found a way to win. This time last year she had Serena on toast until she wilted in the heat. Can she find that devastating form again?
Li - brilliant win over Wozniacki, that makes three Slams she has reached the QFs in. Can she go one further though? Leads Venus 1-0.
Venus W. - didn't play that well against Schiavone, but does she ever in Melbourne (at least lately)? It's only her second venture into the quarters here since 2003 when she lost the final to sis.
Henin - how many more things can fall into place for her? Found a way to beat Wickmayer when looked in trouble, but has complained her body is aching as a reaction to playing so many matches again. Might have to oppose her next round, despite leading the h2h 13-2.
Petrova - scrappy win over Kuznetsova, maybe not as pretty as her win over Clijsters where she was ruthless. Waiting for her to crack upstairs, she's finally got her body in full working order, just worried about between the ears.
Zheng - has had the tougher run through than Kirilenko, beating three seeds in style. Came back from 2-4 to beat Wozniacki in straight sets. I think she has a lot left.
Kirilenko - that heavily strapped left thigh makes you think how long before it goes properly. Outlasted Safina in a battle of the crocks, played two reality easy matches between that and her win over Sharapova. Hasn't gone this far before in a Slam, any further will be a great 23rd birthday present for her.
Still happy with my position on Azarenka, but it will be a tough task beating Serena in current form.