Roger has not won a slam title since Australian Open 2010. Which to be fair is not really that long ago.

Federer has still been consistent @ the slams

FO '11 - Runner-Up
Wim '11 - 1/4 final
UO '11 - 1/2 final
AO '12 - 1/2 final
FO '12 - 1/2 final

So, clearly Feds is still part of the elite pack.

Q1.What are the chances Federer will win a 17th major?

Q2.By what year, would you say Federer will need to win a slam before his chances will end?