Albert Einstein once defined insanity as doing the same thing over and over while expecting different results. Based on that logic, predicting anything other than a Mercedes win at this weekend's race in Austria -- the second in as many weeks to be held at the Red Bull Ring -- just might validate Einstein's point.
Yet the raw data from Friday practice for Sunday's Styrian Grand Prix suggests Red Bull are now the favourites and Mercedes has slipped to second. That's a big turnaround from this time last week, when Mercedes finished Friday with a 0.6s advantage over the rest of the field and looked to have a comfortable margin in the race despite regular Safety Cars.
This week, Mercedes' best time in the second practice was another 0.6s faster than the equivalent session seven days ago, but Red Bull has found over twice as much to move Max Verstappen 0.043s clear of Valtteri Bottas at the front of the field.
So is there concern at Mercedes? And if so, what has changed?
Red Bull fight back
The first thing to note is that Lewis Hamilton was not happy with his car in the second practice session when the fastest times were set. He complained of a problem at the rear of the car and inconsistencies in its handling.
When a six-time world champion says something's wrong, you have to listen. Mercedes responded by sacrificing a large part of the second practice session to check cross weights on the car and review its setup. Finding nothing obviously wrong, the team sent him back out on track with a much more rigorous investigation set to take place this evening in the hope of finding the source of the imbalance.
"It felt relatively normal, but it was quite far off [in pace], so there's a lot of work that needs to go on in the background to try and figure out why," Hamilton said. "I was feeling good in practice one, and the start of practice two felt pretty good, and then it just started to drop off.
What would a reverse-grid race have looked like this weekend?
"Others out there are quick, and Valtteri's obviously got good pace. Hopefully tomorrow it will be a bit better."
So that helps explain Hamilton's 0.688s gap to Verstappen, but it doesn't account for Red Bull's ability to close the gap to Bottas. The driver from Finland, who won last week's race at the Red Bull Ring, had no such complaints, yet all of his 0.5s advantage over Verstappen from last week's qualifying appears to have gone missing.
It's worth adding the usual caveat that single-lap pace during Friday practice is often misleading, with varying fuel loads and different engine settings muddying the waters, but, if anything, this week's second practice session was more representative than normal. That's because the threat of thunderstorms on Saturday and Sunday means there's a chance, albeit small, that qualifying will be completely washed out and the grid will be formed on the results of second practice.
That meant teams used higher engine settings than normal and a number of drivers used an extra set of soft tyres -- which are usually allocated for final practice on Saturday morning -- on Friday afternoon. Bottas said his lap on his second set of soft tyres "still wasn't full qualifying," but Mercedes admitted to running in more powerful engine modes than normal for a Friday session.
It looks as though Red Bull did the same, with Verstappen losing less time to Bottas on the straights and in high-speed corners than in qualifying last week. Nevertheless, the majority of Red Bull's advantage still came in the slow speed corners, especially Turns 3 and 4, indicating that the team has started to hone the strengths of this year's car.
It should also be noted that Red Bull has brought a rear wing upgrade to its car this weekend aimed at improving top speed and minimising some of the instability in corners seen last weekend. Combined with higher track temperatures than we saw in qualifying last week, it may be that Verstappen was able to find the Red Bull's sweet spot while Mercedes lost sight of its.
But the higher-temperature theory doesn't really stack up over long runs, where Mercedes also appeared to lose its advantage despite track temperatures being slightly lower than during Sunday's race. Differing run plans between the two teams on Friday made a direct comparison difficult, but Verstappen, using mediums, held an edge of 0.2 over Bottas, using softs.
Aside from anything else, it may just be that we didn't get to see Verstappen's true race pace last week due to his early retirement. Teammate Alex Albon, who ended up taking the fight to Mercedes last weekend, was considerably slower than Verstappen on Friday (again on different compound tyres, using the hard before switching to the soft), so it could be that the biggest anomaly from the past seven days at the Red Bull Ring was not Mercedes' lack of pace today, but Verstappen's poor performance in qualifying last Saturday.
If he is only now unlocking the true pace of the car, it's possible that we could have a much closer title fight than we first thought.
"We had much better feelings than last Friday. We learned more about the car," Verstappen said. "We weren't so happy last week, that's why we tried to fix some things. So far, it's much better. The direction we took seems to be the right one."
More would usually be revealed in qualifying, but with Saturday's running expected to be wet at best and a complete washout at worst, we may have to wait a little longer for more definitive answers. The early signs, however, are that we should see a much more competitive Red Bull team this weekend.
Is Ferrari still in the midfield?
Hopes that Ferrari would make progress by rushing upgrades through for this weekend's grand prix were not given an immediate boost based on Friday's single-lap pace. Charles Leclerc finished the session ninth fastest, one second off the pace, and Sebastian Vettel was a further 0.9s off in 16th place after having his fastest time deleted for exceeding track limits.
But there were signs of hope in the long-run averages, with Leclerc and Vettel only 0.3s off Verstappen using the same medium compound tyres over comparable nine-lap runs. That tallies with the relatively competitive showing we saw from Leclerc during Sunday's race, but in terms of qualifying pace the team still lacks engine power and straight-line speed.
"We are definitely struggling on that and that's why also the race of last week was so difficult to overtake," Leclerc said. "But we are trying to work as much as possible with what we have got at the moment and hopefully we will change it for the next few races."
Crucially, Vettel and Leclerc looked quicker over long runs than the McLaren, Racing Point and Renault drivers. But combined with what we know from last week and the impressive pace shown by Racing Point and McLaren over a single lap on Friday, there's a chance Ferrari will again struggle to make the top 10 in qualifying.
"I think we found a few things on high fuel towards the end of the day, the last run especially, so this is positive," Leclerc said. "Let's see whether tomorrow or after tomorrow, depending on the weather, if we are able to gain the lap time we gained on high fuel also on low fuel."