It's fair to say that certain elements of Mercedes German Grand Prix strategy left fans confused... luckily, James Vowles can explain.

First off, the German team’s strategist, who has been kept very, very busy of late, reveals the thinking behind the decision to leave Lewis Hamilton out that little bit longer at a time there remained uncertainty over the weather.

"We took the soft tyre at the beginning of the race with the intention of running very long and Lewis in the end did the longest first stint of anyone," explains strategist James Vowles in the latest edition of Pure Pitwall. "We were continuously monitoring and talking to him about how the tyres are and what the state is with them, to make sure we could push them long and there was still life left in the tyres.

"We knew there was a chance of rain," he continues, "but we believed it to be very light later on and one of the best things you can have is fresh ultrasofts, rather than a very used soft tyre in those conditions.

"When we stopped we were 25 seconds behind Vettel but Lewis did a fantastic job and managed to pull all that lead pack back to within 11 seconds of him, so a gain of 14 seconds overall. The correct decision, put ourselves in a very good position in order to then go on to win the race."

Explaining the fact his team was confident the rain, when it arrived, would only affect a specific part of the track, Vowles continues: "On the pit wall sat with us is our expert weather forecaster. He is continuously monitoring all the available systems to him to understand what rain is around, how it will form and what will happen during the course of the race.

"What he could see is even at the beginning of the race there was a rain cell forming just four kilometres away, so very, very close but it didn't hit the circuit.

"But, he could predict the nature of which the cells were coming in," admits Vowles, "how they were expanding and therefore where it would hit if it were to expand, which was Turn 6. He informed both engineers, who then informed the drivers and allowed us to prepare in the best way possible for what was then going to happen. He also forecast the rain would be light and not covering all of the circuit.

"We knew that the conditions were very difficult out there for both Valtteri and Lewis and they were really struggling," says Vowles of the decision not to switch either Hamilton or Bottas to Inters or full wets. "You saw a number of cars in fact both spinning, Leclerc doing a full 360, and Vettel crashing on lap 52 of the race. It was difficult.

"There was one to two laps that were into inter conditions, around lap 51 and 52, everything else was very much still faster on slicks if not extremely difficult. And we knew that. We knew that the rain was passing, that was the worst of it and you had to remain on slick tyres in order to maximise your benefit.

"At one point, on lap 46, there was every single compound used, there was a medium, a soft, an ultrasoft, an inter and an x-wet," he adds. "Just to show you how difficult the conditions were out there to both predict and work with.

"Both Valtteri and Lewis did an incredible job, kept it on the track and ultimately that is what led to a fantastic one-two."

Explaining the mix-up when Bottas pitted during the safety car, Vowles says: "We had a few seconds to react with Valtteri, we got him into the pit lane and he did a great job. What then happened was a miscommunication on what tyres were required and intermediate tyres were called, that was incorrect.

"We knew ultrasoft was going to be the correct tyre, the conditions right then and there were intermediate but was going to happen was after the safety car appeared, they were 100 per cent going to be back into ultrasoft or dry conditions.

"What then happened is given the high-pressure situation, the guys did a fantastic job and something we purposely train for. They dealt with it in an extremely calm manner, got the correct tyres for Valtteri's car of the correct specification and all four were bolted to the car. The car left the pit lane in a very short period of time afterwards."

And the confusion over Hamilton...

"On lap 52 Valtteri was in Turn 15 when the Safety Car was deployed, that's around a two and a half second reaction time that we have to get him in before he's at the pit lane entry. With Lewis we only had a few seconds more than that. So, it's not very long in order to coordinate two drivers, an engineering team and all of the pit crew to come out into the pit lane with the correct tyres. It creates a huge amount of radio traffic and indeed too much, it was mostly chaotic during that point in time with a lot of transmissions everywhere.

"As a result of it, there was a miscommunication to Lewis, he understood that he should go back out on track and he completed that. He drove across the grass and got back out on track again.

"The reality behind all of it is that actually, that turned out to be extremely fortunate given the issues that we had with Valtteri and the tyres at the pit stop," Vowles admits. "It put Lewis in the lead of the race and those tyres were able to recover. We could indeed have stopped next lap as Kimi did but decided to keep him out there and keep those tyres going. It was his best chance of winning the race and it worked out very well."