Power Rankings (Jan. 18): Dandy Andy and Super Serena

You might agree with us (you probably won't), but throughout the Australian Open Yahoo! Sports is going to keep tabs on who's hot and who's not in the men's and women's fields.

Our power rankings list will be updated daily to reflect the progress of the big names and beyond as they battle it out for the first Grand Slam of the year.

Here is the first set of rankings as we prepare of the opening day of Slam action in 2009.

Men

1. Andy Murray: Rapidly improving Scot is the man to beat on hard courts

2. Roger Federer: 13-time Slam winner is looking for a flying start to '09

3. Rafael Nadal: World No. 1 has never gotten past the semis in Melbourne

4. Novak Djokovic: Defending champ hopes to repeat his glorious triumph

5. Juan Martin Del Potro: Rising superstar is desperate for a Slam breakthrough

6. Jo-Wilfried Tsonga: Last year's finalist ended 2008 strongly and is feeling confident

7. David Nalbandian: Sydney winner can be anyone on any given day, but Nalbandian needs consistency

8. Marin Cilic: Already won a title this year (Chennai) and has the game to contend

Women

1. Serena Williams: Won in 2003, 2005 and 2007. Notice a pattern?

2. Venus Williams: Has reached the Australian Open final just once in nine visits

3. Jelena Jankovic: World No. 1 hasn't won a major but has Melbourne pedigree

4. Dinara Safina: Wants to put past struggles Down Under behind her but has tough draw

5. Ana Ivanovic: Made the final last year but has struggled for form in recent months

6. Elena Dementieva: Olympic champion wants to bury her reputation as a Slam choker

7. Caroline Wozniacki: Danish stunner is climbing fast and looks ready for stardom

8. Victoria Azarenka: 19-year-old scored first career title in Brisbane last week