BlueB
Legend
This is a very interesting spread sheet!A better statistic would be the percentage of all their matches ended in retirement. Even though he may have retired a lot of matches, he has also played a lot as well so that should be taken into consideration. Djokovic has a retirement rate of about 1.7% of all his matches played.
http://www.tennisabstract.com/reports/retirementReport.html
On a bit of analysis, it's easy to conclude that Djokovic is somwhere in 47th place, tied with Kohlshreiber, so just above median.
Another interesting fact is that the true, undisputed NATION of QUITTERS are FRENCH, see for yourself
Traditional warrior nation, Japan, is in shameful 9th place.
Argentina doing pretty badly too, with Nalby saving the day.
True warrior of the tour is Fed, with over 1000 matches played and 0 retirements!