Novak Djokovic and Andy Murray have used 2016 to emphatically prove why they are the two highest ranked players in the men's tennis.
The pair have been at the top of their respective abilities since the turn of the year, meeting in the finals of the Australian Open, Madrid Open, Internazionali d'Italia and, most recently, the French Open.
Djokovic holds a 3-1 advantage from those encounters, his Roland Garros triumph securing a career Grand Slam and making him just the third man to hold all four major titles simultaneously.
Few would bet against the pair continuing their head-to-head rivalry at Wimbledon on July 10.
Not since 2010, when Tomas Berdych was defeated in straight sets by Rafael Nadal, has any player outside the 'big four' reached the All England Club final.
Nadal's hopes of a third Wimbledon title have already been ended by a wrist injury that forced him out of the French Open.
Injury troubles have also blighted world number three Roger Federer's year.
The Swiss spent almost three months out of competition at the start of 2016 and did not take part at Roland Garros due to a back injury.
Following his return, Federer, usually so majestic on grass, has endured disappointing losses on the surface to Dominic Thiem and Alexander Zverev this month.
While the 17-time grand slam winner cannot be written off, his form suggests a run to the Wimbledon final in pursuit of an eighth SW19 title may be a bridge too far for the 34-year-old.
Federer suffered defeat to Djokovic in the 2014 and 2015 finals, with the Serbian's last defeat coming a year prior in 2013. His conqueror: Murray.
That triumph remains the most iconic of the Briton's career, ending the 77-year wait for a home winner of the tournament.
Following the 2012 US Open, it was Murray's second grand slam win, with the influence of coach Ivan Lendl - an eight-time major winner during his playing days - of key importance.
The pair reunited in June following Murray's split with Amelie Mauresmo and Lendl has a clear vision for their renewed partnership.
"In tennis there is the career Grand Slam, there is four in a row, there is the calendar year Grand Slam and the Golden Slam," said the Czech. "He [Djokovic] has a chance to do that this year. Obviously Andy and I would like to ruin those plans if we can.
Those words were backed up when Murray won a record fifth title at Queen's, ensuring he heads to the All England Club on a high.
The 29-year-old had to battle from a set and a break down to see off Milos Raonic in the final, the Canadian instantly reaping the benefits of having John McEnroe on his coaching team.
McEnroe, a five-time Wimbledon champion, stated his belief Raonic is a future major winner when announcing he would team up with the world number seven.
Wimbledon presents a prime opportunity for that to become a reality, while promising Austrian Thiem will also be in the hunt for a first grand slam.
The 22-year-old picked up his seventh career title in Stuttgart this month, though a disappointing defeat to world number 192 Florian Mayer in the semi-finals of the Gerry Weber Open shows his potential vulnerabilities.
However, it is Djokovic and Murray who are undoubtedly best placed to continue their dominance of the ATP Tour this year - it will take something special to stop either of them.