What To Watch For In Melbourne

© Getty ImagesRoger Federer is bidding to claim a fifth Australian Open title.

ATPWorldTour.com previews storylines to watch for at the 100th edition of the Australian Open.

Big 3 Lead The Way – Since 2007 Roland Garros, the trio of Novak Djokovic, Rafael Nadal and Roger Federer have reached the semi-finals together 21 times. Of the 21, nine have come in a Grand Slam tournament, including three of the past five.

Here’s a look at the semi-finals. Bold below indicates eventual winner:

Note: This is the first time at the Australian Open in 1991 that the top three seeds have all won at least three Grand Slam titles. In 1991, the trio of Stefan Edberg (4), Boris Becker (4) and Ivan Lendl (8) each won at least three Slam titles.

The World No. 1/Reigning Champion – Djokovic is coming off a career-best 70-6 season in which he captured an ATP World Tour-best 10 titles in 11 finals, claiming three Grand Slam crowns (Aust. Open, Wimbledon, US Open) and a record five ATP World Tour Masters 1000 titles. He was 64-2 after winning his first US Open and he finished the season with a 6-4 mark. He was 21-4 vs. Top 10 opponents (4-8 in ’10) and six of his wins came over Nadal and four over Federer. He took over the top spot on July 4 after capturing his first Wimbledon crown (d. Nadal). His first loss came to Federer in the semi-finals at Roland Garros on June 3, which snapped a 43-match winning streak going back to 2010 Davis Cup final (41 in 2011). After the loss, he then won 16 in a row.

One year ago the Serb was ranked No. 3 and his incredible season began in Melbourne, dropping only one set (vs. Dodig in 2R) en route to his second Aussie Open title (’08). In his final three matches, he defeated No. 6 Tomas Berdych, No. 2 Roger Federer and No. 5 Andy Murray. In both of his title runs in Melbourne he’s only dropped one set.

Federer-Nadal Domination – Since Nadal won his first Grand Slam title at Roland Garros in 2005, he and Federer have combined to win 22 of the past 27 Grand Slam tournaments (except '08 & '11 Aust. Open - Djokovic; '11 Wimbledon - Djokovic; '09 US Open - del Potro; '11 US Open - Djokovic). During that stretch, Federer has won 12 Grand Slam titles and Nadal 10. This is the second Grand Slam tournament since the 2004 Aust. Open that Federer or Nadal are not seeded No. 1. In that Grand Slam tournament, Andy Roddick was the top seed. At last year’s US Open, Djokovic was top seed. This is the first Grand Slam tournament since 2005 Roland Garros they are seeded in the same half of the draw. That year they squared off in the semi-finals in their first Grand Slam meeting.

Grand Slam King – Federer is the all-time leader in men’s tennis with 16 Grand Slam titles and he's accomplished the feat in a span of 34 Slams played since winning his first title at Wimbledon in 2003. His eight-year streak of winning at least one Grand Slam title came to an end last season although he was runner-up at Roland Garros. Overall he is 16-7 in Slam finals with six losses to rival Nadal and the other to Argentine Juan Martin del Potro.

Tomic Leads Aussie Hopes – Mark Edmondson is the last Aussie singles champion in 1976. Teenager Bernard Tomic is the top Aussie player ranked No. 37. The 19-year-old is making his fourth straight appearance in Melbourne (4-3 mark) and last year he lost to No. 1 Nadal 62 75 63 in the third round. Lleyton Hewitt, 30, is making his 16th straight appearance in Melbourne (27-15 record) and his best result was a runner-up in 2005 (l. to Safin). In his 14 other showings he has never advanced past the 4R. Matthew Ebden,, who finished in the Top 100 last season (at No. 86), is the No. 2 Aussie and he’s looking for his first win in Melbourne (0-2).

Grand Slams Streak – Federer is the only player in this century to play in every Grand Slam tournament in singles. This will be Federer’s 49th consecutive Grand Slam tournament. Wayne Ferreira holds the all-time record of having played in 56 straight Slam tournaments from 1991-2004.

Grand Slam Champions in Field – Four-time Australian Open champion Roger Federer is one of seven Grand Slam winners (accounting for 36 GS singles titles) in this year's main draw. Here are the active Grand Slam tournament champions in the draw:

Active Players to Rank No. 1 – Djokovic, who became the 25th player in the history of the South African Airways ATP Rankings to rank No. 1 on July 4, is one of six players in the draw to rank No. 1:

+ Start of tournament (Jan. 16)

All-Time Grand Slam Champions – Federer is the all-time leader on the Grand Slam singles titles list:

Will There Be a Breakthrough Winner? Since 2006 the Australian Open has been won by a Top 3 ranked player: Federer three times (four total) Djokovic twice and Nadal once. The last player outside the Top 3 to earn the title was No. 4 Marat Safin. Here’s a look at the players in the draw who have reached at least one Grand Slam final and are still looking for their biggest career title:

Doubles Champs – Bob and Mike Bryan have finished No. 1 for seven of the past nine years and are five-time winners of the Australian Open, including last year. Overall they have 11 Grand Slam titles, which is tied for Open Era lead with Aussies Todd Woodbridge and Mark Woodforde.