The guy on the left is a perfect 41-0 in 2011 (43 in a row dating back to 2010) and if he wins the semis, he will take over the World No. 1 ranking (win, lose or draw) in the Final. If he wins the title, it'll be his third career Grand Slam title, 2008 and 2011 Australian Open were the other two.
The guy on the right is perhaps the greatest player to ever play the game-- a 16-time Grand Slam champion-- owns an UNBREAKABLE RECORD of holding the No. 1 ranking for 237 CONSECUTIVE weeks-- everything that can be done in the game of tennis, he has done-- HOWEVER-- for the past 6 months or so he's had to settle for being a third wheel and relinquish the spotlight to the guy on the left as a new rivalry with the current World No. 1 is evolving and it doesn't bear his name-- AND HE DOESN'T LIKE IT!
So it's time to settle it in the only place it can be settled-- the tennis court....