EDIT: Meant to put this in player discussion.. oops.
Ok I'm writing this because over the past year I've kept posting the same facts over and over again in an attempt to dispell certain myths about Djokovic that people have carved in stone and now refer to rather than look back at said facts. This mainly relates to Novak's physical issues and retirements etc.
Novak was a weakling who could not last a 5th set
look at these stats here -
You will actually see that NONE of Novak's retirements so far have occured in the 5th set of a match. The closest thing is his retirement in the 4th set of the AO against Roddick. In fact more than half of the retirements came in the 2nd set of the match. One came at 6-6 in the first set, which would also rather dispell the myth that he only quits when he feels he can't win the match. He also quit whilst 2 sets to 1 up against Davydenko.
On the other hand look at his record when the match DID go to 5 sets. It's 15-5 (to put this in perspective, 5 set warrior Nadal is 15-4, and overall novak is 7th on the list of all time reliability) Only 3 of these 5 set wins have come since the start of 2011, meaning prior to his remarkable improvement he was still 12-5 in 5th sets, and remember he didn't retire in any of those 5 losses.
stats here http://www.atpworldtour.com/Reliabil...reer-List.aspx
Furthermore look at the stats for a few tournaments. take Wimbledon 2007 where these were 4 back to back matches for 20 year old Novak -
R64 Delic 6-3 3-6 6-3 7-6 (2h 19mins)
R32 Keifer 7-6 6-7 6-2 7-6 (3h 39mins)
R16 Hewitt 7-6 7-6 4-6 7-6 (4h 12mins)
QF Baghdatis 7-6 7-6 6-7 4-6 7-5 (5hours)
He then retired against Nadal at 1 set all and a break down in the 3rd, but those were pretty tough matches for a so called weakling to make it through. There are also several other long matches around this time and earlier, including his final set tiebreak match vs Stepenek at the US Open in the 2nd round 2007 (6-7 7-6 5-7 7-5 7-6).
Then there's the match in Madrid 2009, a match which went 4 hours for 3 sets of tennis where Novak was standing at the end, just unable to take any of the match points he had. That year after the retirement in Australia, Djokovic went on to play nearly 100 matches, and not withdrawing form any events on his schedule, something which every other top player failed to do - they all had to skip events. Djokovic reached 5 masters finals, but only won Paris at the end of the season (beating nadal on the way) when everyone else was getting tired despite Novak having played more matches. He also won Basel just prior to this beating Federer. His tiredness towards the end of the season apparently caused him shoulder problems and prompted him to change service motion which then ruined his 2010 season, where he spent too much energy just scraping wins (see his Dubai win that year where he was awful but ground it out) in my opinion, this had a big effect on him going backwards physically from an impressive 2009 (I think he had hired Muster's old fitness coach that year)
Now here's the thing. When has Novak had serious injuries, keeping him out of the game? Most of his issues have come out of nowhere in one match. In my opinion, Novak has been a bit of a hypercondriac, when things are going hard sometimes he's had a habit of thinking "I'm finished" or if he's hurting he'd overreact to that and let his mind make it worse. We know with a strong mind you can push through the pain barrier and move towards your goal, you just need to be disciplined and focused. We also know that your mind can play tricks on you and make you think you're feeling better or worse than you really are. The mind is a very powerful thing and has a huge effect on what the body can or can't do. The fact that now he is stronger in the mind and much more focused on his goal of winning, has had a huge impact physically.
Many people are cynical about him, but I don't think the link between a strong mind and strong body should be overlooked, and nor should the fact that Djokovic had stamina in the past - his retirements were weird situations that seemed to happen for no real reason other than maybe he wasn't feeling great that day and couldn't tough it out because his determination was lacking. If people can lift cars off people through sheer mind over matter, why can't someone get strong enough in the head to fight through the pain barrier and get their second wind?