F1 in 2021 has delivered a title battle fans have long been waiting for.
Max Verstappen and Lewis Hamilton went wheel-to-wheel from the outset in Bahrain and, after 16 mostly thrilling races, just six points separate the pair in the standings.
But who will be feeling more confident heading into the remaining races? RacingNews365.com considers the factors at play, with insight from the paddock and comments from all parties involved.
On paper, it's rather simple. As already touched on, Verstappen holds a six-point advantage over Hamilton following the Turkish Grand Prix.
With Red Bull lacking pace to Mercedes throughout the weekend, in dry and wet conditions, it has to be considered a 'win' for second-placed Verstappen to come away with the title lead.
Hamilton, of course, followed Verstappen's Russian GP move by taking an engine penalty (although not the entire power unit), meaning he started back in 11th. From there, he rose to as high as third, but a late switch to fresh Intermediates dropped him to fifth – much to the Briton's frustration in the heat of the moment.
Hamilton did, at least, receive a favour from outgoing teammate Valtteri Bottas, who took eight points away from Verstappen with a dominant victory and the fastest lap.
Mercedes boss Toto Wolff was full of praise for Bottas after the race, describing his performance as "10 out of 10" and highlighting the "vital role" he can play in supporting Hamilton.
But the same can be said about Verstappen's teammate, Sergio Perez, who robustly defended against Hamilton and made his recovery all the more challenging, possibly even preventing him from scoring a podium finish.
It remains to be seen just how much the 'number two' drivers can influence the outcome of this year's championship…
W12 vs RB16B
Having upped their game in 2021 and gone toe-to-toe with Mercedes for the majority of the season, the Turkish GP was a rare 'off' weekend for Red Bull.
After Friday practice, team boss Christian Horner described a balance "mish-mash" on a much grippier Istanbul Park track surface, compared to the 2020 event.
Despite an improvement overnight, Verstappen and Perez still weren't entirely comfortable for Saturday's running and Mercedes claimed the top two positions in qualifying, prior to Hamilton's penalty.
Red Bull advisor Helmut Marko went as far as to suggest that sister team AlphaTauri had the more competitive package over the course of the weekend, putting it down to them "simply getting the setup better".
Second and third with Verstappen and Perez, and Hamilton out of the picture in fifth, is a result that surely would have been snapped up by Marko and Horner on Friday night.
However, Red Bull's Istanbul struggles aside, it does appear that Mercedes have made progress with their car in recent weeks, despite no obvious updates being applied.
Hamilton described the W12 as "great" to drive but could not put his finger on why, other than Sochi and Istanbul favouring Mercedes over Red Bull.
"We haven't done anything to the car, so I don't really know why that is the case," said Hamilton.
"I think the two tracks that we've just driven on maybe suited us a little bit more. If the car continues to behave as it has this weekend, that will be good for us."
Wolff offered a "carefully optimistic" outlook for Mercedes.
"I don't think you can say that with an absolute conviction," he commented, when asked if Mercedes will have the faster car for the title run-in.
But he added: "I believe that we have a really good package now. The car is competitive and was very competitive this weekend.
"If it wasn't for a grid penalty, I think we could have had every chance to finish first and second – and that would have meant eight points more."
Mercedes vs Honda
But in addition to the chassis, engine performance is key to this conversation.
The Red Bull camp made plenty of noise after Sunday's race, with Horner and Marko piqued by Mercedes' apparent jump in straight-line speed over the second half of the season.
Horner described it as a "surprising" and "significant" step forward.
"Whereas we could match them with smaller wings previously, now we can't get near," he explained.
"We saw that at this circuit, where Lewis in particular had a significant straight-line advantage with a bigger rear wing on the car, [so] we've got to maximise our package as best we can."
He added: "If you look at some of the speed deltas on the back straight, at some points it was 15 to 20 km/h [faster], which is more than if there had been DRS."
Marko has since confirmed that the FIA will take no further action over Mercedes' engine, after they looked into the situation.
Performance vs reliability
However, while top speed is clearly no issue at Mercedes, the same can't be said for reliability.
Bottas took on his fourth and fifth engines of the season in Italy and Russia respectively, before Hamilton exceeded his 2021 allocation in Turkey.
Hamilton's change came after reports of Mercedes recently taking their entire stock of current power units back to Brixworth for extensive analysis, with claims that Bottas has even lost a fresh engine from his pool.
Wolff admitted over the Turkish GP weekend that Mercedes "are not looking at stockpiling good engines" for no reason, and that they need to work through "little gremlins" that have appeared throughout the season.
"You can see across all of their teams they’ve got some reliability issues that they’re managing, which is unusual for Mercedes," Horner added.
"Their performance is still incredibly impressive, so whether one comes at the expense of the other, I don't know…"
Hamilton, though, has trust in his team to get any issues under control.
"I don't really give any energy to it," he said. "It's not my job to worry about that stuff, so I let the guys focus on that, worry about it.
"My engine is in good condition. My first engine, I think, did six races. We still have engine two, and I think engine three is still there.
"As far as I'm aware, hopefully I don't have to [use a fifth engine], but I can't predict what's up ahead."
And what about the prospect of another engine penalty on Red Bull's side? "Not under normal circumstances, no," said Horner.
A costly change, or even worse, a retirement, could be the deciding factor in such a close championship fight.
The mental game
Hamilton vowing not to spend any time worrying about Mercedes' engine issues leads on to another critical area: mental strength.
Hamilton has plenty of title-winning experience, given the seven championships under his belt, albeit most of them with only an inter-team battle to consider.
Verstappen, meanwhile, is involved in his very first title fight.
It recently prompted Hamilton to comment that he "empathised" with Verstappen about the pressure he may be feeling, which the young Dutchman promptly laughed off, declaring that it shows "he really doesn't know me".
Horner also chimed in, using Verstappen's impressive performance on home soil in the Netherlands, with the weight of the nation on his shoulders, to argue that the 24-year-old is more than capable of dealing with the pressure.
"I don't see any change in him at all," said Horner, when asked about Hamilton's comments.
"Max is a young guy, he's going for it, he's got nothing to lose. He's not sitting there with a bunch of World Championships defending the title. He's the challenger, and I think that that's the way he's attacking this championship.
"When you see the pressure he was under with a home crowd in Zandvoort, you don't get bigger pressure than that. I think the way he handled that in particular was truly impressive."
Horner added: "He's just really enjoying and relishing this battle."
Hamilton himself claimed that he is feeling "very chilled", even after the late-race drama in Istanbul as he and Mercedes debated whether to pit for a fresh set of Intermediates.
"I don't feel any pressure," he insisted, adding of the Turkish GP weekend: "I don't like losing points, but that's just the way it is."
On goes the battle, with six races coming thick and fast between now and the end of November.
First up is the Circuit of the Americas, where Mercedes have triumphed in five of the past six races. Hamilton has won the races five times, first with McLaren in 2012, then four in a row between 2014 and 2017 with Mercedes.
"Austin is a track we like, and it's another opportunity, but I am under no illusion that this is going to go very much to the end in the Drivers' Championship," Wolff stated.
Horner agreed with Wolff, but added his optimism for Brazil and Mexico.
"Austin has been a Hamilton stronghold for quite a few years now, but then Mexico, Brazil… the higher altitude races have tended to be quite strong for us to the past."
Beyond that, the visits to Qatar (Losail International Circuit) and Saudi Arabia (Jeddah Street Circuit) are new, while several changes have been made to the Yas Marina Circuit ahead of the season-ending Abu Dhabi Grand Prix.
"I'm really not sure what to expect from the last three, so it's going to be fascinating, but we're gonna have to be at the very top of our game," said Horner.
"We'll do our simulation, we'll do our homework and we'll do the best job that we can.
"I think we've got to take it one race at a time."
Roll on Austin… and place your bets!
It's time for the latest episode of the RacingNews365 podcast, with F1 journalists Dieter Rencken, Thomas Maher and Mike Seymour discussing Lewis Hamilton's strategy drama and much, much more from the Turkish Grand Prix.