why he struggled in the past?
1. Federer wasn't as old.
2. Nadal wasn't washed up.
3. Murray like Djokovic is a late bloomer. The two of them will fight for the titles in the future.
^^^ Exactly ^^^^
Also, he could not serve for about a year - he had more double faults than aces one year - 2010?.
He could not play a slam with 5 set matches and have anything left in the SF until 2011.
He is still not a great tactician or volleyer. Look at the 2012 AO Final and watch the 4th set tie breaker. He had Nadal 5-2 or 5-3 and on 2 consecutive points had Nadal completely out of position and stabing just to float the ball back. Djoko had both feet in the court when he drove Nadal deep off the court with great drives. On both points, Djoko backed up - let me repeat that - leading 5-2 in tie breaker and drives Nadal into a slice floater from 10 feet behind the baseline and Djoko backs up on 2 consecutive points. He went on to lose both points and the tie breaker. Djoko won a hard fought 5th set but the 5th set should never have been played. Djoko was very lucky to win this match and little tactical mistakes like this can kill you.
More proof of bad tactician - watch 3rd set of Wimby final Djoko won over Nadal. Nadal backed up and looped the ball - Nadal basically said I cannot beat you playing grass court tennis so I will back up and play clay court tennis on a grass court. Djoko did not figure this out in the entire 3rd set which Nadal won. Djoko did finally figure it out in the 4th set and actually attacked a bit more.
Djoko is basically a run and gun guy. It is working for him now because he is physically superior to Nadal and Federer but he is no where near as good a tactician as either and Federer is a far more complete player. Even Nadal's tactics - hit it with heavy spin to the backhand until I break you down is more tactically sound - also Nadal will change things up when losing by coming in or trying to flatten it out. Federer is the best tactician in the game.