This article was first published today in our bespoke Sports newsletter The Fixture. You can sign up in seconds to receive it straight to your inbox every weekday here 

If you watched the BBC's three-part series Gods of Tennis, which aired just before this year's Wimbledon championships, you might have been struck by how many pure rivalries there were in the sport back in the 70s and 80s.

In the programme, there were some clunkier associations such as Arthur Ashe and Billie Jean King: two players representing marginalised groups who, it was argued in the first episode, might have had a more vocal presence had Ashe joined forces with King, rather than ignoring her campaign aimed at giving women greater equality in the game. The whys and wherefores of such an argument need the context of time and place ascribed to them: Ashe was having a difficult enough job establishing himself as that rarest of breeds – a black man competing with some success in a white-dominated sport.

The second and third episodes dealt with the rivalries between John McEnroe and Bjorn Borg and Martina Navratilova and Chrissie Evert. The Fixture recalls the epic Wimbledon final between McEnroe and Borg with a childlike wonderment. The household had come to a standstill as my mother, father and elder sister sat glued to the sofa. My younger brother and I would venture in and out of the house every so often – at various junctures caught up in the tension and, at others, utterly indifferent to it. On these occasions, we'd wander outside for a play with our friends only to return 20 minutes later to discover that their marathon was still being run. Stop to think about a tennis match – and just how much you can fit into the time that two players will be on court for – and you get an overwhelming sense of just how time has no meaning in a fight to the death such as that which McEnroe and Borg were engaged in.

Pick up a racket and play two sets of a club rubber and the appreciation for what these protagonists put themselves through becomes even more acute. It is prevalent in the burgeoning rivalry between Carlos Alcaraz and Novak Djokovic. Their final at the Cincinnati Open on Sunday night conjured up memories of McEnroe-Borg's face offs of 40-odd years ago. 

The Herald:

Djokovic appears legitimately confounded by his Spanish opponent's ability to flick a wrist to a ball to fetch the seemingly un-returnable winner down the line. They are two players who almost have the perfect antidote to each other's styles. Matches between the two thus far have taken on the appearance of 80s video game Pong but if that conveys the impression that this might be boring or a chore to watch then it is the wrong one. Their rallies are full of attacking tennis, of daring shot choices and elan – they cancel each other out for the most part in what appears to be a zero-sum game before one or the other demonstrates their fallibility by making a mistake.

But there is another dimension to their 'rivalry' and the single quotes are there for good reason. The two men genuinely seem to like each other – they are kindred spirits, like two great thinkers who are ideologically opposed but who cannot help but appreciate each other's genius.

In many ways, they remind you of the rivalry between Navratilova and Evert documented in Gods of Tennis: pitted as East v West combatants, the pair were good friends at the outset of their rivalry before Martina had to convince herself to hate her American counterpart in order to get the better of her, before later in life they reconciled with each other and became great friends again.

At 36, Djokovic's age would suggest that his rivalry with Alcaraz will not reach the point where the pair are engaged in an outright war of attrition. The Serb admitted he had been pushed to the limits of his physical capabilities in Cincinnati and hinted at retirement after his defeat to Alcaraz in the Wimbledon final in July saying: “He’s going to be on the tour for quite some time. I don’t know how long I’ll be around.” 

For now let's just enjoy their head to heads for as long as they last.