It's at the Canadian Grand Prix that we'll find out if Mercedes' secret tyre test really gave them the Great Leap Forward. The race at Isle Notre dame in Montreal is a universal favourite on the calendar, both for spectators visiting the city and those at home.
In the past it has delivered some epic races, none more so than Jenson Button's outstanding drive in 2011 when he was last on Lap 40 and finally overtook Sebastian Vettel on the final lap, pressuring him into a glorious mistake that lit up a fairly drab season.
There have been incidents and accidents; Jarno Trulli tipped Robert Kubica into a barrel roll that dominated highlights packages for two years - Alexander Wurz always used to wreck his car at Turn 1 on Lap 1 (which has claimed very few pile-ups of late), there's the Champions' Wall after the final chicane that sucks drivers into it. We've had Nigel Mansell switching his engine off waving to the crowd on his final lap and temporary turf flying everywhere: "Oi don't think they've got a flag for turf" was Derek Warwick's classic line when the short-term landscaping got swept onto the track by the passing traffic.
It is a circuit infrequently used, with 'aggressive' tyre-eating tarmac that creates carpets of marbles by half distance and with a speedy pitlane entrance, the temptation to have multiple pit-stops could see cars make so many pit-stops they're scratching around for tyres by the end of the race. That is why the Mercedes tyre performance will be the thing most people focus on.
In Barcelona they qualified 1st and 2nd on the grid and finished 6th and 12th (that in a race where cars on the front row usually win) and this is another circuit where they should have a good stab at the front row. If they can convert that into two podiums then the howls of (rightful) indignation will grow stronger.
Ferrari were very competitive in Barcelona, so by now people will have put the two and two together that they had their own advantageous Pirelli test beforehand. What is most irritating for Ferrari is that they are tarred with the same brush as Mercedes - 'secret tyre testers' yet they went to the great trouble of using their Corse Clienti sportscar team and none of their frontline drivers. So they've got 90% of the grief but only 60% of the data.
Going by their Spanish performance, they should be strong in Montreal. With that long back straight, multiple stops and DRS - everybody is going to be concentrating hard on race set-up - and so the long runs on Friday afternoon, FP2 ,will hold the real key. Except... the weather forecast for Friday and Saturday is none too warm, 16C and 18C with the chance of rain on both days. Sunday looks to be sunny intervals (predicted on Weds) but as we know, this can all change round.
Red Bull probably had a better Monaco than they expected, although they've never really bossed the Canadian GP. Again, the rough nature of the tarmac is likely to show up any flaws in their set-up, and hand the advantage to cars that are light on their tyres. Thus the prospect of a Kimi Raikkonen win or a Force India podium is a real possibility. Certainly if you wanted a cheeky little bet then an each-way on a Force India driver might be worth contemplating.
Kimi Raikkonen will have the opportunity to punch Sergio Perez on the driver's parade - or encourage someone else to do it - so that should make for some interesting TV. Sergio really ought to put him on the spot and ask him about it in front of the TV cameras. Kimi wasted points in Monaco by trying to resist a driver who had nowhere else to go at the tunnel chicane. Squashing him into the barrier wasn't really going to work - as he found out. Alonso used his head and turned what was going to be a points defecit into a points advantage by letting Checo go.
The tunnel chicane is not unlike the chicane at the end of the long back straight on the circuit Gilles Villeneuve, there is only one line through and if someone stuffs their car up the inside you can't both get through at once. The big difference is that the escape route is easier and you have a lot more time to see anyone coming and make your mind up what you're going to do.
The other Lotus driver managed to cover himself ingloriously - and with carbon fibre - by slamming into the back of Daniel Ricciardo in Monaco. That's after the other three accidents that involved just himself. Canada is another street circuit, high on the attrition rate, and so the frabricators at Enstone will be holding their breath for another weekend's toll. The only good news is that there is three weeks between the Canadian and British GPs. The gap is part of Bernie's 2013 Year of Confusion, the season where nobody can work out what's going on - tyres, engines, costs, sporting regs and grands prix intervals.
Caterham and Marussia will be keen to get their cars to the finish line in Canada because this represents one of their best chances at a high place finish - thanks to the high probability of retirements. So even though the emphasis will be all at the front, should there be a hefty spate of retirements, then it will be all action at the back as well.
Lewis Hamilton has often gone well in Canada and team boss Ross Brawn says he's still adapting to his new engineering team (and their mid-race driver tuition!). This will certainly be the opportunity for Lewis to put an end to Nico's qualifying dominance. However as with most of the races this year, the big subject of conversation is going to be tyre degradation.
"Because of the high degree of tyre wear and degradation, we would expect to see a number of different strategies at work," said Pirelli's Paul Hembery. " Last year the 'sprint' approach won the race, but with so many different parameters at work, the teams will have to analyse the data - not to mention the weather forecast - very carefully before committing to any particular tactics. Often a flexible approach works best in Canada, so we can also expect many teams to be leaving their options open, allowing the drivers to really make the difference when it counts."
So thinking drivers like Button, Alonso and Vettel could have the edge over a tyre conserver such as Raikkonen. Going one stop fewer may be advantageous on a circuit where it's difficult to pass, but when it's a short pitlane entrance, throwing extra stops into the mix and 'sprinting' may be the best option. On Sunday we'll be able to count the tyres...