What happened to Nole? From my point of view, nothing so surprising.
1. He simply ran into the best players at these tournaments in the last decade while they were in very good form.
7 Roland Garros and 7 Wimbledon championships don't lie. Novak has won 0 at Roland Garros and 1 Wimbledon, so it's very difficult to get past these record holding champions at these events.
2. The key in a major is being able to pace oneself throughout the 2 weeks. Many look great in the first week only to falter at the business end. Essentially, one wants to be playing their best tennis in the semifinal and final where the toughest opposition usually is. I don't pay too much attention to a top player who appears to struggle in early or mid rounds, but still wins, as long as they don't expend too much energy (like too many 5 setters, 4 or 5 hours). If anything, it can make them tougher in later rounds.
3. One must be in fairly good shape going into the major, or it is very difficult. Giving winning performances at both Roland Garros and
Wimbledon has never been easy. Since 1970 only 3 men have done it. Borg 3 times, Nadal twice and Federer once. As one gets older, it gets even more difficult. Nadal and Djokovic put in top performances at Roland Garros and had a busy clay season prior to that, with Nadal coming out on top. From an energy standpoint, I think they both were not able to give their absolute best at Wimbledon.
Roger Federer announced his priorities before the season began. He wanted to be primed for Wimbledon and the Olympics. I think Federer has realized by now that if Nadal makes the final at Roland Garros, it is not going to go his way. I said before Roland Garros started that I would be surprised if Federer went beyond the semifinal if Nadal was still in the picture. Why expend so much energy to get clobbered again? Especially as he approaches 31 years of age. Better to exit from Paris, and move on to the grass and let Djokovic and Nadal fight it out. So Federer still had a good amount in the tank for his run to the Wimbledon final.
Nadal looked tired at Halle, and not much better at Wimbledon. He was putting more effort into following the Euro Cup tournament than into Wimbledon. Playing football with his friends and parties late into the night. The knee tendinitis stuff is chronic. It's always going to bother him more when he gets tired. After Wimbledon, after presumably getting more injections for his tendinitis, he took a vacation and went fishing and jet skiing with his friends. He was still not in condition to play at the Olympics after that and his doctors told him that he needed another 15 days rest without any
sporting activities and so, missed the Olympics. Perhaps he will be back for Toronto or Cincinnati.
Djokovic gave pretty much the same effort for the clay season as Nadal. He failed in 3 clay finals to beat Nadal for varying reasons, but lost all the same. After a long Roland Garros final loss he did not compete in any ATP event until Wimbledon. He came to Wimbledon only a bit fresher than Nadal. His matches all the way up to the semifinal were against relatively easy opponents and he disposed of them without much undue effort. But I think that hurt him a bit in that he was not as tested as much as he should be when thrown in against Federer.
Also, the cloudy and wet weather during the entire fortnight did not help Djokovic. It kept the grass fresher and soil moister with the result being a more "slippery" court and lower bounces. Djokovic, like Nadal, profits from the grass being worn down to dirt, especially all the way across the baseline and hot dry conditions that bake the soil and make it higher bouncing. In those conditions, they can use their great movement to run down almost every ball and they don't slip on the grass.
At Wimbledon 2012, it was rain, rain, rain, and not much sun. The grass stayed in pretty good shape all the way through to the final. Only the grass near where the players serve behind and just in front of the baseline was worn to dirt. Once near the doubles alley, the grass was barely worn. The roof only exacerbates the conditions as it becomes more humid. And we saw Djokovic, Nadal, and Murray slipping again and again there, and also when pushed to come to the net. Federer? Hardly any slipping at all. His east-west movement may no longer be as good as it was, and not as good as these players outstanding movement, but Roger's footwork remains much among the best. Federer makes the correct minor adjustments in footwork that need to be made on the more slippery surfaces such as grass and as we saw, the blue clay of Madrid. He glides across the surfaces, and doesn't rely on hard planting of the feet to give him the leg power like Djokovic does on hard court. When Nole starts slipping, his overall confidence to hit his shots goes down. He misses relatively easy overheads, volleys, and other footwork dependent shots. And then once that happens he gets into a more depressed state of mind.
All of these factors were enough to help him lose.
I expect Novak Djokovic to be able to get back to his normal game on the hard courts. He doesn't have quite as much advantage at the summer hard court season in North America because the courts are generally faster/lower bouncing than say in Australia or Miami. But still, he should be a force, unless his confidence has taken too much of a hit. I don't see that happening. I expect him to be at his best. Will it be enough? Only time will tell. There are so many good players on the hard court. I would not be surprised at any player among Djokovic, Murray, Tsonga, Berdych, Del Potro, Federer, Nadal being in the picture at the US Open. There can be only one winner. Who will it be?