Mercedes technical director James Allison believes the outcome of the 2019 season will be determined by the unrelenting development race between the German team and its arch-rival Ferrari.
Mercedes and the Scuderia are once again engaged in an intense battle, with each outfit alternately enjoying an edge over the other depending on the venue and circumstances.
Lewis Hamilton has put the Silver Arrows squad ahead of its Italian counter-part thanks to two consecutive wins in the last two races, but Allison admits that Mercedes' current edge over its opponent is a very small margin and one that can turn on a dime.
"These are all small margins, which is why the championship has yo-yoed one way and the other," says Allison.
"It's quite interesting to note that in the 12 races we have had so far, only five of them have been won by the car that most people agree was quickest on that weekend.
"Seven of them have been won against the head: three of them we have stolen, two of them Ferrari has stolen and two Red Bull have had."
As usual in the competitive world of Formula 1, a team's development rate must be sustained throughout the year. Between Mercedes and Ferrari, there will be no respite insist Allison.
"It's been a very intriguing year where these very small differences, maybe an error, maybe a moment of particular genius or just sheer good fortune or ill fortune is determining who comes out smiling at the end of the race," adds the British engineer.
"None of it is set in stone; the development race over the remainder of the season, who stays strong, who doesn't make mistakes, who can keep their chin up the longest ... all the clichés you want to roll out, that is actually what is going to determine this utterly compelling and brilliant year.
"None of us know, none of our opposition know who it's going to favour and that's what makes it so exciting.
"It's frightening too but that's what makes us look forward to this second part of the year, to see whether it can be us at the end of the year standing with smiles on our faces, knowing that we did a really good job in a season that put us to the test like no other."
Allison obviously knows by now the underlying qualities of Mercedes' W09, but he also acknowledges the car's weaknesses relative to Maranello's SF71-H.
"It tends to vary a little bit track to track and race to race as the development race has ebbed and flowed through the season, but there are a few patterns that are relatively constant," he says;
"Certainly for a few races now we have been missing just a few horsepower to a Ferrari that has had a very impressive rate of development through the year.
"We are probably on average better through the corners than Ferrari on most tracks, sometimes they take a bit from us in the low-speed but medium- and high-speed we normally prosper relative to them.
"I would say they have tended to be a wee bit stronger than us at tracks that have tended to be strongly rear limited, but we are talking small margins, and us the opposite.
"We've tended to have better pit stops, they have tended to have better starts, although we have appeared to put that right in recent races from a lot of work from the good guys in the controls department in the factory."
Gallery: The beautiful wives and girlfriends of F1 drivers
Keep up to date with all the F1 news via Facebook and Twitter
