How Mercedes pulled off an 'impossible' tyre strategy in Monaco GP

Pirelli's wet and intermediate tyre compounds have been criticised for over-sensitivity and a lack of range, yet Hamilton was able to complete 31 laps on full wets even as the track quickly dried then jump straight to slicks.

There were occasions shortly prior to that when Hamilton's laptimes on the extremes matched those behind on the intermediates, which in the past would not have been possible given the significant variances in the rubber.

Pirelli motorsport boss Paul Hembery explained to Autosport: "We did make some changes over the winter to the full-rain tyre.

"The idea was to close the gap between the two compounds, and it would appear from this particular case it has worked.

"The decision to make changes followed comments from the drivers saying they were reluctant to go on the rain tyre, saying the gap was too big [to the intermediates] and they were losing performance.

"But then there was also a case of vice versa in that they were coming onto the inters a little too early because they felt in certain parts of a bigger circuit - not Monaco - you could gain a performance on the drying part of the track.

"So the overall thinking behind it was to try and improve a little bit the performance of the full-wet tyre.

"It was hard to do. We had a couple of days testing [at the Paul Ricard circuit in January] and we made a small step.

"I don't think we can claim it was a fundamental change, but it was in a certain direction, and possibly we have now seen that direction was the right one."

Following Hamilton's one-and-only stop, he then managed 47 laps on a set of the new ultra-soft compound - a tyre designed to be deliberately short-range yet used by the winner for well over half a race distance.

Again, such a stint did not appear feasible going into the race.

"It was more than anybody had run in free practice, or indicated they could run in free practice," Hembery acknowledged.

"They obviously put it on when the track was still cool and had some damp areas, which played a part in extending the life of the tyre.

"It's also not abrasive around Monaco anyway. The wear levels were low all through the practice sessions.

"But it was certainly a few laps more than what we anticipated, that's for sure."

Prior to the race Hamilton had declared the ultra-soft tyre to be nothing more than "a super-soft with purple paint".

Taking Hamilton's remarks on board, Hembery said: "I'm sure he is happy about it now.

"But the ultra is family derived, and the lap differential between that and the super-soft was about eight tenths [of a second], which is what we wanted.

"It's not a full-out qualifying tyre because we have to use it elsewhere.

"You could do something very extreme for Monaco, no doubt about that, but then you wouldn't be able to use it in Singapore or Canada.

"If you wanted to look for absolute performance then for Monaco you would be able to produce something very different."

Hembery had only praise for Hamilton and Mercedes for making a one-stop work in such unusual circumstances.

"We were sat looking and wondering whether that was what Mercedes were trying to do, which was to stay out until the track dried," added Hembery.

"Of course, it is Monaco where overtaking is difficult, but it still relied on that very long stint on the ultra-soft.

"Mercedes took an aggressive approach to strategy, and it paid the ultimate dividends by bringing them the win, and all credit to them for that."