(CNN) The ageless Roger Federer defies logic as his domination of tennis continues into his sporting dotage.
The Swiss, who turns 37 in August, has managed the previously unthinkable: producing some of the best tennis of his life at an age when most other players have long since faded from view.
Federer's Australian Open triumph in January extended his collection of grand slam titles to a record 20.
And he shows no sign of slackening off.
Federer is the favorite to add an unprecedented ninth Wimbledon men's singles title this fortnight -- 15 years after his first
We've taken a look at three key areas for Federer, and how he has improved his serve, his backhand and his performance under pressure.
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There's an obsession with speed in tennis. Sitting court side, you'll see other spectators constantly looking to the speed gun, always wanting to know: just how fast was that serve?
Perhaps that's understandable, as there's something visceral about a ball whizzing through into the dark green backstop.
But perhaps you should know that speed isn't everything.
Federer doesn't have the biggest serve in the sport, and that doesn't diminish its greatness.
First of all, we should note that his serve isn't at all slow.
But he also hurts opponents with placement, spin, variety and deception. Imagine if Federer had always been reliant on the oomph of his serve.
If he had been, he might now be fretting, deep into his thirties, about losing some pace. As it is, that's not a concern for Federer. As the numbers show, his serve has only improved of late: he is winning more points and games and hitting more aces.
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Federer's backhand is a blend of the old-school and the ultra-modern.
It's old-school because he plays a classic one-handed stroke, and contemporary because he has changed the way he thinks about, and plays, the shot.
Federer's resurgence in his mid-thirties has been based, in no small part, around upgrading his backhand.
By changing his mindset and also tweaking his technique, Federer has turned his backhand into more of an attacking shot.
In the past, Federer was perhaps a little too fond of slicing the ball rather than playing through the ball.
Now, though, he has shown an increased appetite for being aggressive with the most elegant shot in tennis.
Looking at the numbers for when Federer is returning serve from the advantage court, you get a sense of the improvement in his backhand.
Though some of the shots he plays on that side will be forehands, especially when serves are hit down the "T," this is an instructive graphic.
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In the white heat of Wimbledon's Centre Court, or indeed in any other stadium around the tennis map, Federer won't panic.
You'll often hear about his artistry and skill, but perhaps tennis should be talking more about his mental fortitude, and his ability to play his best tennis when it really matters: in tiebreaks and deciding sets.
Once a teenage hothead, Federer has become a calm and composed figure, in control of his emotions.
It's sometimes said that, as athletes age, they lose their nerve as as well as their speed and their strength, but that's plainly not the case with Federer, who so far in 2018 has won a higher percentage of tiebreaks and deciding sets than over the course of his entire career.
Perhaps we would not be surprised -- you don't win so many Wimbledons, and other grand slam titles, if you keep on losing your head when you're under enormous pressure.
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What's more, Federer's opponents know he often raises his level at the moments of greatest intensity, and that must be unnerving.