How Serena Williams, Maria Sharapova, Victoria Azarenka can take No. 1

Serena Williams faces Sloane Stephens in the quarterfinals on Wednesday. (Asanka Brendon Ratnayake/Icon SMI)
The No. 1 ranking on both tours is up for grabs at the Australian Open. Roger Federer has a slim chance to dethrone Novak Djokovic, while Maria Sharapova and Serena Williams are gunning for current No. 1 Victoria Azarenka.
For the men, Djokovic can retain No. 1 by beating Tomas Berdych in Monday's quarterfinals. If he fails to do so, Federer can retake the top spot by winning the title. Sorry, Andy Murray. You're not part of this conversation yet.
The scenarios are a bit more complicated for the women, though by virtue of her fourth-round exit here last year, Williams is in the best position. She can take the top spot for the first time since 2010, a span that's seen her come back from toe surgery and the resultant complications in 2011.
Here are the cleanest scenarios for the women's No. 1:
Azarenka: Win the Australian Open.
Williams: Make the final or make the semifinals as long as Sharapova doesn't win the title.
Sharapova: Win the title or lose in the final as long as Williams loses in the quarterfinals and Azarenka doesn't win the title.

Contributor, SI.com Nguyen is a freelance writer for SI.com, providing full coverage of professional tennis both on and off the court. Her content has become a must-read for fans and insiders to stay up-to-date with a sport that rarely rests. She has appeared on radio and TV talk shows all over the world and is one of the co-hosts of No Challenges Remaining, a weekly podcast available on iTunes. Nguyen graduated from the University of California, Irvine in 1999 and received a law degree from the University of California, Davis in 2002. She lives in the Bay Area.