Mercedes strategy chief James Vowles has confirmed that the Silver Arrows successfully pulled off a plan to trick Sebastian Vettel into taking an unfavourable track position in qualifying for the Azerbaijan Grand Prix which helped the constructors' champions lock out the front row.
Ahead of the final Q3 runs, Lewis Hamilton and Valtteri Bottas pulled out of the garage, with Vettel following them, only to pull over at the end of the pit-lane in the position reserved for practice starts.
This highly unorthodox practice had a huge impact on the segment as it gave Hamilton and Bottas each a tow, which the Finn used to take pole and ultimately a win, while Vettel ran in clear air and could only qualify third, despite Ferrari's apparent advantage on Baku's big straight.
"In qualifying the effect of the tow is very significant," Vowles said in Mercedes' 'Pure Pitwall' debrief. "In Baku this effect is very extreme.
"It's around about four tenths of a second] in Baku, so a significant amount that you can or cannot be on pole as a result of it.
"Over the last few races you've seen almost a Mexican standoff in the pit lane, everyone has their engine fired up and everyone's looking at each other but who's going to go out first?
"In Shanghai you saw that we left very late and other cars weren't able to do their lap because they were so keen on getting the tow that the flag came before they started their lap.
"In Baku we were very conscious of this effect could well dictate whether you were on pole or not.
"What we decided to do therefore is send our cars out a little bit earlier which would pull the whole train of cars behind us – that worked – and then do a practice start, simply so that we did not end up at the front of the queue because we felt the effect was so powerful.
"This is taking enormous risks and indeed we only crossed the line several seconds before the flag as a result of this.
"But in this situation it worked. We pulled over to the left-hand side, other cars came past, Vettel led the pack and didn't have a tow on this particular occasion, allowing our cars to get in a nice position behind competitors and benefit from both a tow and good track position."
Vowles confirmed that the ruse had been concocted well in advance of Saturday's qualifying getting under way.
"This sort of plan doesn't go without quite a bit of discussion beforehand," Vowles added. "Especially with the drivers to make sure they understand, accept and agree [with] the plan.
"For them, it's very difficult. You're asking them to break up what is the normal routine of going out for Qualifying 3 – a very high pressure situation – and doing something different.
"They understood exactly what was required of them and they did a fantastic job."