MEXICO CITY -- Throw away the Formula One formbook, it's not worth anything this year. Just as it looked as though Max Verstappen was clearing a path towards his first world title, Lewis Hamilton and Mercedes hit back in qualifying for the Mexican Grand Prix.
You would have struggled to find anyone in the F1 paddock willing to predict an all-Mercedes front row ahead of Saturday afternoon's session, yet that's what we'll have for Sunday's race. What's more, it will be Hamilton's teammate, Valtteri Bottas, who will start on pole position, creating the potential for another team orders debate on Sunday afternoon.
But before we get ahead of ourselves, what went wrong for Red Bull?
Immediately after qualifying, Red Bull's management blamed AlphaTauri's Yuki Tsunoda for Verstappen missing out on pole position. Tsunoda, who is contracted to Red Bull and drives for its junior team, found himself on the wrong part of the track at the wrong time, compromising the final qualifying laps of Sergio Pérez and Verstappen.
In a normal Q3 session, Tsuonda would have been on a fast lap of his own and therefore too far down the road to trouble the Red Bulls, but a grid penalty for an engine change at the start of the weekend meant his purpose in the session was rather different. Because he was destined to start from the back of the grid regardless of his lap time, he had been sent out on track solely to give his AlphaTauri teammate, Pierre Gasly, a slipstream on the pit straight.
Having completed his job -- Gasly went on to secure fifth on the grid thanks to the tow -- Tsunoda was on his way back to the pits, but just so happened to end up in the high-speed second sector of the lap at the same time as the Red Bull drivers. Although his AlphaTauri was way off the racing line as Perez closed in on him, his presence and the dust he threw up unsettled the Red Bull in Turn 10 and forced the Mexican into an error.
Verstappen, who was behind Perez, thought he was approaching an accident as Perez left the road in front of him and backed off the throttle accordingly, ruining his own lap.
"I think we got Tsunoda'd," Red Bull team principal Christian Horner said. "Both drivers were up on their last lap. Max was up two and a half tenths, I think Checo was just under two-tenths up and I don't understand why he was just cruising around at that part of the circuit.
"It's disappointing because it affected both the drivers and they are both pretty annoyed. But we're still second row of the grid and can have a great race from there."
Speaking to the media after the session, Perez added: "I was annoyed because in Q3 he shouldn't be there. But it is what it is."
To be fair to Tsunoda, there wasn't much more he could have done to get out of the way of the Red Bull drivers. He drove completely off the circuit to make way for Perez and the fact there was no investigation by the stewards into whether he blocked Perez tells you everything you need to know about whether he was in the wrong.
Speaking to media after getting out of his car, Tsuonda seemed oblivious to Red Bull's frustration.
"I didn't mess up the Red Bull -- it was just a mistake by themselves," he said.
"I don't know about Max? Did I hold up Max as well?" he asked his press officer as it dawned on him he might be in trouble with his bosses.
Once he was shown a video of the incident, he was still surprised to hear blame was being directed at him.
"I went outside [the track limits] and I couldn't do anything more than that. I mean, I don't know, where should I go?
"I had a countdown [from my engineer about the closing speed of the Red Bulls], but I was in the sector two.
"I don't know. If I had another chance, I'd do the same thing. I don't know, what should I do?"
Mercedes hits back
Blaming Tsunoda also ignores the fact that Red Bull simply wasn't quick enough to beat Mercedes when it mattered in Q3.
The 0.2s time advantage Horner claims both his drivers had found prior to the incident would still have been short of the 0.350s improvement Verstappen needed to beat Bottas to pole and the 0.467s margin Perez needed.
Perhaps Verstappen and Perez would have found even more time in the final sector, but if you calculate Verstappen's theoretical best lap -- based on adding all his best sector times together -- he would still have fallen short of Bottas by over a tenth of a second and been shy of Hamilton by a couple of hundredths.
So where did Mercedes' pace come from?
"We were all surprised," Mercedes team boss Toto Wolff said. "It seemed pretty obvious that Max would take pole, and that it would be a fight between us and Checo [Perez] for the other positions, and then we could see that qualifying really came towards us.
"On the medium [tyre in Q2], we started really to outperform them, and at no point in Q3 did they have a lead on any of the laps. Also I believe that in the last lap [before they came across Tsunoda], they were behind.
"So yeah, that makes the sport for me so fascinating, that from one session to the other, performance can swing, and we've seen it to our detriment in Austin, and now it has happened to our advantage here in Mexico."
Horner believes Mercedes found some of its unexpected qualifying pace by solving the turbo-related issues it suffered with in Mexico's high altitude in previous years, meaning the assumption that Red Bull was the favourite going into qualifying was perhaps misplaced.
"They were very quick, very quick," he said. "I think we could see yesterday that their engine, they've addressed the issues that they had previously here. So they've obviously managed to address that.
"I think we underperformed in Q3, but it's still very, very tight. I think in the race tomorrow, again it's going to be very tight. They've just got a good straightline speed here, which is going to be tough."
Wolff confirmed some "tuning" of the engine had unlocked more performance this year.
"Yeah we have optimised it for these conditions," he said. "At the end, you're trying to extract power unit performance throughout the calendar, and the outliers are somehow difficult to take account for.
"But it's more a tuning question. It's not that we've put the engine upside down. It's just we better understand why it didn't perform in high altitude."
Meanwhile, Verstappen looked to issues with his own car, rather than Tsunoda or Mercedes' engine gains, as the reason why he will line up third on the grid tomorrow.
"I just think we were really slow and had terrible grip in Q3," he said. "I think my last lap, we recovered it a little bit by getting the tyres into a little bit of a better window, but we were still not what we would have liked and how the car was behaving in all the practice sessions.
"So that was a bit of a mystery. But then tomorrow we maybe race on different tyres anyway so I expect the balance to be good again."
Tactics and team orders
The race is set to be fascinating, with Bottas starting ahead of Hamilton and the two Red Bulls tucked in behind. The long run from the grid to Turn 1 often results in drivers starting further back benefiting from a slipstream, although there's still no doubt you'd rather be starting from the front row than the second.
The grid order also raises the question of whether Mercedes will use team orders if Bottas retains his lead over Hamilton at the end of the first lap. Prior to the weekend, all the talk was about whether Red Bull would deprive Perez of a home win if he was ahead of Verstappen, but on Saturday night the same question was being asked of Wolff and Mercedes.
"I'm a racer, and I feel that such discussion is something that is always just disappointing in a way, but sometimes the circumstances oblige that," Wolff said in response.
"But we will address it and discuss it first with Valtteri and Lewis, because they're both involved in such discussions. And then we will see whether the race scenario actually obliges us to make any such call."