Phil wrote: ↑03 Oct 2017, 08:53
I'm not sure if this is entirely sound yet. I'm inclined to agree that pitting Bottas first would have been risky - yes - he would have come out on the more durable tire and quicker (fresher tires vs old SS), but Vettel clearly had a lot of pace and was running a lot quicker than Bottas. If Mercedes had pitted Bottas early, then there was the risk that Vettel would have stayed out longer and done an "overcut" on Bottas. If that had worked, then Vettel could have run on his "optimum strategy" without pitting early and he likely would have had even better pace on his last stint and crucially ended up closer to Hamilton and Ricciardo.
Like this, they could see if Vettel could overtake Bottas and if not, compromise his stint length to make him less of a danger on the SS-stint. Maybe the hope was that by pitting Vettel early, they could possibly force him into a 2-stop, or a slower 1-stop.
What Mercedes didn't know, but it was reported by AMuS in their post race analysis, is that Vettel was running a "all or nothing" race. He was driving his Ferrari at the bear limit without any fuel conservation or regards to tires. This meant that when he caught up to Ricciardo, he was already way in minus in regards to fuel. The strategy at that point was to overtake Ricciardo and go into extreme lift and coast. The overtake didn't work out and Vettel started extreme measures to save fuel. Apparently, he was coasting 600-800m before the braking points on the straights. The tires were less of a factor at that point, contrary to what Vettel said post-race.
Let's put it this way, from this graph
http://www.f1fanatic.co.uk/2017/10/01/2 ... ap-charts/
You can see Vettel both passes Perez at lap 20 and has a 4 second gap on Bottas at lap 21, in clear air closing down Bottas, so that is his base pace until he catches Bottas
From here
http://www.f1fanatic.co.uk/2017/10/01/2 ... test-laps/
we can see he did his fastest lap of the first stint on a 96.3 second lap, it actually looks like he slows before he really gets in dirty air straight away, so likely his tires overheated a bit and he had to back off and gain a little slower, tires likely running out of life a little, before being stuck behind Bottas at a 97.3 before choosing to pit immediately.
While Vettel's time using frankly too much fuel and on faster tires was a 94.5, Bottas's first lap on fresh softs was a 96.1, or considerably faster than Vettel was managing on the old softs at around 96.9 before he got slowed down by Bottas and faster than the 96.3 that was vettel's fastest lap.
At this point multiple people had pitted and improved pace by a fair amount and those were guys who pitted early so had to be more conservative. Ferrari aren't stupid, you have tires that suit their car better and will easily last half a race, but the best strategy for anyone at any time(but often ignored) is to use your tires before switching. If you want to change strategy, use every inch of tire then change, don't just throw away tire life and lap time and switch onto a longer stint. Ferrari stayed out but were at best 1 second a lap faster than Bottas, that isn't a big gap, I mean it is and Bottas was very slow, even at Vettel's fastest, using more fuel and pushing like crazy he only matched Hamilton's lap time on lap 21. The issue is that gap wasn't close to big enough to beat the undercut.
AS Mercedes tactical guys they should see the times Vettel did from lap 20, see his biggest gain was 1 second a lap and said, Vettel will pit the second he gets held up and if he pits first he'll come out ahead. If we pit first, we'll come out ahead easily, hell the 3 laps before he did a lap time matching Bottas he was only half a second faster, which again suggests that 96.3 lap was unsustainable.
Merc got everything wrong for me, they wanted to be on softs asap, they could easily do over half the race distance, the lap time difference was easily going to be enough. Hell once they saw the 96.3 on lap 21 they could have pitted bottas right then, when he was faster than Vettel that might have forced Vettel to pit 4 laps earlier than he did but he'd have a gap to close on Bottas before passing on track. If Vettel waited 5-6 laps to their preplanned pitstop time then he'd have to gain a likely 7-8 second gap using up his best tire life to catch Bottas.
Whoever made the decision to keep Bottas out screwed the pooch completely. I still think Vettel would have most likely passed Bottas, but it would certainly have been harder and contrary to Max's assessment that Hamilton wouldn't fight him hard for 1st due to the championship, Vettel would have had the opposite situation. Bottas is fighting to beat Vettel in the championship and team wise, it's better for Hamilton if Vettel stays behind, Bottas had a reason to be very aggressive where Hamilton didn't.
This is all before you realise that Mercedes could simply say, it won't make a different to Bottas to do what Vettel was doing, pit, use a higher engine mode, use more fuel for 5-10 laps then if and when Vettel passes him, save fuel/lower engine mode.
