There have been a number of memorable matches at the ATP Tour World Finals in recent years, in tennis’ second highest-tier tournament behind the Grand Slams. The ATP Tour World Finals was first introduced under a different name in 1970 by the International Lawn Tennis Federation, before the ATP took over in 1990 and renamed the competition to what it is now known in 2009. Roger Federer currently holds the record number of Finals’ triumphs with six, with his latest coming in 2011 against Jo-Wilfried Tsonga. That match was an excellent one, but did it make our list of the most memorable ATP World Tour Finals matches? Let’s find out…