The two parts of Roger Federer's game that have simply gone away in the past year that are just not up to par with how he was earlier in his career:
Converting break points (I barely ever see him attack a break point anymore. He is so passive and borderline cowardly)
2nd serve (Opponents, such as Gulbis today, who aren't even that great of returners can just destroy his 2nd serve. A couple of years ago, Federer was regarded as having one of the best 2nd serves in the game. Now, it seems like opponents are licking their lips waiting for it.)
Converting break points (I barely ever see him attack a break point anymore. He is so passive and borderline cowardly)
2nd serve (Opponents, such as Gulbis today, who aren't even that great of returners can just destroy his 2nd serve. A couple of years ago, Federer was regarded as having one of the best 2nd serves in the game. Now, it seems like opponents are licking their lips waiting for it.)