Men's tennis has regularly been blessed with great rivalries since the Open Era began in 1969.
Legendary battles often ensued between Bjorn Borg and John McEnroe in the late 1970s and early 1980s.
Similar titanic tussles were witnessed between McEnroe and Ivan Lendl throughout the 1980s.
And men's tennis fans have been spoiled in recent times with fantastic matches on a regular basis between Roger Federer and Rafael Nadal whilst Novak Djokovic has also come to the fray in the last couple of years.
2012 has seen a new potential rivalry emerge. That of Andy Murray and Novak Djokovic.
This is a head-to-head that should have got fans talking a long time ago. Both Murray and Djokovic are 25 years old, with Murray having been born a week earlier in May 1987.
Whilst Djokovic won his first Grand Slam in 2008 and then had a remarkable 2011 where he won the Australian Open, Wimbledon and the US Open, the Scot seemed destined to never win a Grand Slam.
He lost his first four grand slam finals between 2008 and 2012, before finally breaking his duck at the US Open last month, where he beat Djokovic in five enthralling sets.
It sealed the culmination of a fantastic summer for Murray where he reached the Wimbledon final and then recovered to win Olympic gold four weeks later.
So why is Murray v Djokovic the next big rivalry in men's tennis?
That aforementioned age of 25 is the key thing. Both men are now entering their physical peak as shown by their matches in which they both never seem to show any signs of poor fitness.
Contrast that to the ageing Roger Federer at 31, who despite being World Number One can't continue to live with the power of Djokovic and Murray for much long than the next 18 months you feel.
And what of Rafa Nadal, the other legendary grand slam champion of the last decade? His knees don't seem to be in a good way at all and he hasn't played since a shock second round defeat to Lukas Rosol at Wimbledon in June.
Other players such as David Ferrer, Juan Martin Del Potro and Jo Wilfried Tsonga are either not consistent enough or beset with too many injuries to push to the very top.
The style that Murray and Djokovic play is another key factor to their rivalry which is set to dominate men's tennis.
If you look at their two matches this year in the Grand Slams, firstly in the Australian Open semi-final which Djokovic won in five sets and then the US Open final which Murray won in five sets, the level of movement and combination of attacking and defensive strokes from the both of them is absolutely breathtaking to watch.
Ivan Lendl, Murray's coach has brought a new level of aggression into the World Number Three's game and that is why Murray finally broke his grand-slam duck.
Djokovic and Murray are pretty much unique in the fact they can belt the ball back at each other for close to five hours and still look as though they have just been out for a light jog.
Nadal used to be up to this but it remains to be seen if this latest knee injury will prove too much for him to cope with Djokovic and Murray.
Both players also have complete all-round games, which is necessary to get to the very top in men's tennis these days.
Sure, each of them has weaknesses but both possess killer forehands and backhands, quality serves and an ability to control the game at the net.
When these players are on top form, nobody can touch them right now except each other.
The score in their 16 meetings currently stands at 9-7 to Djokovic. Expect that figure to swing back and forth over the next few years as a Serb and a Scot battle it out for supremacy in the world of men's tennis.
Who would have predicted that a decade ago?
