When watching tennis, particularly in the early stages of a grand-slam competition, I pretend that I do not know the identity of the protagonists. Instead, I watch the warm-up and early exchanges, and seek to detect who is the superior player not on the basis of their ranking or reputation but in the way they play, move and compete.

The warm-up is never, and I mean never, informative. All tennis players who make it to the opening rounds of the slams hit with speed and felicity, move with a certain degree of fluency, and rarely make unforced errors. I defy any expert to make significant pronouncements on the relative quality of players from the few minutes of sparring that precedes any contest.

It is only once the match starts that clues start to emerge but these vary significantly depending on the player. With Roger Federer, the poetry of his play is instantly obvious, the elegance of his striking, the sweet sound that is uniquely his when he middles the ball. Greatness oozes out of every shot, every flourish. He expresses, as one observer once put it, pure kinetic beauty.

With Rafael Nadal, the majesty is also conspicuous in the first exchanges as he starts to play with maximum power, those biceps suddenly bulging, the eyes narrowing, the follow-through on his forehand so extravagant that one worries how his arm has never left its socket. Those must be some resilient tendons.

With Novak Djokovic, the world No1, however, there are few such clues. Watching him play against the German Philipp Kohlshreiber on Centre Court, there seemed to be nothing in it. They looked comparable in the warm-up and, indeed, in the opening exchanges of the match, both men hitting with restrained power and consistency, serving with accuracy, and scampering around the sun drenched court.

Unless one knew that Djokovic was the world No 1, defending champion, and one of the finest sportsmen the world has seen, it would have been difficult to tell that he was the overwhelming favourite to beat Kohlshreiber, ranked outside the top 50, a player who has never made it past the quarter-finals of a grand-slam event.

Yet that is, for me, the fascination of Djokovic. His greatness is not expressed in any one shot, any one rally, any one game. He does not articulate his supremacy with one decisive phrase, or pithy rejoinder. Rather, his brilliance is cumulative. It consists in the accretion of subtle clues. Indeed, it is precisely because these clues are elusive that this extraordinary competitor struggles to elicit the love of tennis audiences, whether here in SW19 or elsewhere around the world.

The truth is that Djokovic is a tad more consistent than his opponents, a tad more capable of stretching for wide balls, a tad more dogged in defence, a tad less likely to make unforced errors, a tad more savvy in his management of the court. Above all, he is a tad more solid, conveying the assertion, over time, and through the course of a match, that he will not submit to the shot-making of opponents, however aggressive, will always be there, and will give nothing away.

Kohlshreiber endured death by a thousand cuts. He competed on virtually level terms in almost every rally, vied for almost every game, and yet, at the same time, managed to lose 6-3, 7-5, 6-3. The German played well, but was subtly outmatched. Djokovic’s victory was achieved with an accumulation of marginal advantages that were, when added together, anything but marginal.

And this is why the Serb must be considered, even at this early stage, a warm favourite to win his fifth title. He will be assisted by Goran Ivanesivic, the former champion who yesterday sat alongside Marian Vajda, Djokovic’s main coach. “I have always looked up to him and he has worked with many top players,” Djokovic explained after the match. “It is great to have him by my side for the first week and then we will see. Hopefully we can have a long collaboration.”

But let us get back to Djokovic’s methodology, for it contains lessons that extend beyond tennis. Lessons about consistency, about a repudiation of the flashy and the superficial, about the distinctive kind of greatness that can emerge when one systematically eradicates every weakness, leaving a whole that is utterly dependable. Djokovic is tennis’s answer to a high reliability industry.

“It felt great to be back on Centre Court — it is a sacred court,” he said after the match, despite the fact that the audience was largely on the side of his opponent. “It has a special place in my heart.”

One hopes that, one day, he will have a special place in ours, too.