The situation of tennis is changing more quickly than decade ago, maybe even several years ago
Since 2008 Nadal's wimbledon win, how many surprises we've alread had?
Very few people would believe Fed could win 4 of his next 6 GS after his tough loss to Nadal in Wimbledon and his two losses were all in 5 setter.
Very few people would believe Nadal could win 4 GS after his miserable year in 2009.
This time of last year, all the people were talking about Nadal's Dynasty, which lasted only several months, if it ever existed.
Even though both 2 experts of this forum claimed that they predicted Djoke's success since 2007, I doubt the success in their definition was as any close as the success Djoker has this year.
Now someone is starting to chant "calendar grand Slam". Personally , I believe Djoker should have, and will have won the Career Grand Slam after his winning RG someday, but we never know what is going to happen next year.
Is it possible that Murray suddenly finds his recipie to success?
Is it possible that someone other than big 4 starts to ruin the party?
Is it possible that Roger rejuvenizes himself somehow?
Is it possible that Nadal improves his serve again as he did in 2010?
Is it possible that something is going to happen beyond my imagination now?
You never know and I don't want to know.
It will be an interesting and exciting tennis battlefield next year . Let's wait and look forward to it.