The 2014 Canadian Grand Prix will go down as one of the most exciting races of the last decade.
Daniel Ricciardo won to record the first grand-prix victory of his career. He joins Gilles Villeneuve, Thierry Boutsen, Jean Alesi, Robert Kubica and Lewis Hamilton in the list of drivers who won for the first time in Montreal.
Nico Rosberg came home in second after driving the second half of the race with no ERS power. It was a great damage-limitation drive, and the 18 points he picked up could prove crucial at the end of the year.
There was drama up and down the field in a race which saw only 11 cars cross the finish line.
But this was that most unusual of things: a Canadian Grand Prix which owes its excitement to DRS.
The drag reduction system, more commonly referred to by its initials, has proved a contentious topic since its introduction at the start of the 2011 season.
It exists because modern cars—from the leading Mercedes all the way down to the backmarking Caterhams—are incredible masterpieces of aerodynamic engineering. The unrivalled cornering speed of F1 cars is down to the intricately designed and tuned wings, bodywork and vanes directing airflow around the car in such a way that it "sticks" to the road.
But these aerodynamic devices rely on the airflow striking them in a smooth, controlled manner. They cannot operate at their peak in turbulent (or "dirty") air.
So they're great in clean air, but once they get close behind a rival they encounter the dirty air coming off the rear of the car. They lose a lot of downforce—and therefore cornering speed.
This means that the cars cannot follow each other closely through corners to be near enough to challenge down the straights using a slipstream alone.
DRS is there to give them an extra speed boost. By changing the angle of the main flap of the rear wing, it cuts drag. Cars get it when they're less than a second behind a rival at a specific point on the track.
Some circuits need it a lot, others not so much.
It would appear we were wrong.
This belief was created by classic races of the past, which featured bags of overtaking at numerous points around the track. Turn 1, Turn 8, the hairpin Turn 10 and the final chicane all saw plenty of action in years gone by.
But watching the race on Sunday, it became apparent that Montreal needs DRS.
All throughout the race we saw (or didn't see, depending on what the producers chose to show us) trains of cars, quicker drivers being held up badly by those ahead. The lap charts created by Keith Collantine of F1Fanatic show this clearly.
We all saw the high-profile hold-ups, but further down the order there were similar situations we didn't see so much.
The two McLarens and Kimi Raikkonen behind Daniil Kvyat in the first half, the Williams and Fernando Alonso behind Nico Hulkenberg in the closing stages and Kevin Magnussen behind Jean-Eric Vergne to the chequered flag are good examples.
Drivers were having an extremely difficult time making passing moves even with DRS.
It takes little imagination to consider what the situation would have been without it.
One of the early highlights of the race was the duel between Rosberg and Hamilton. There was genuine tension and a feeling of expectation every time Hamilton got into the DRS zone and looked like he might challenge for the lead.
After a few laps of pressure, Rosberg locked up and cut the final chicane, adding a little more drama and excitement. In addition to the track action, we were waiting with baited breath to see if the stewards would punish him for gaining an advantage.
But without DRS, the "battle" would have been a dull, tension-free two-car procession. There's no way Hamilton could have challenged Rosberg down the straights in an identical car.
We'd have been far from the edge of our seats as they circled around, Hamilton around seven-tenths of a second behind, waiting for the pit stops.
Also providing a bit of early drama were Hulkenberg, Valtteri Bottas and the two Red Bulls. Running close together, there was always the chance one of them might hook up his DRS and attempt a pass.
As it happened, there was no overtaking here even with DRS. But the tension and excitement was there—without DRS, we'd have been robbed of the "what if?" factor and resigned to the "battle" being another dull procession.
Felipe Massa would have been stuck, too. The Brazilian lost out in the pit stops and emerged behind Alonso.
He got past his former teammate with a beautiful move around the outside into Turn 1 on the 26th lap but would never have got close enough without DRS assistance.
Another great moment we'd have lost, and on this occasion it would have changed the shape of the race later on. Because he got by, Massa was able to close up on the cars ahead and become involved with the awesome battle for the lead in the closing stages.
And that battle for the lead over the last 20 laps would have been the greatest casualty of a DRS-free race.
The fight for first place was between five cars. The sole remaining Mercedes of Rosberg led Sergio Perez, Ricciardo, Sebastian Vettel and Massa.
Perez was too slow through the corners to challenge Rosberg on the straights. So while we were still watching to see if he could stay close enough to Rosberg through Sectors 1 and 2 for DRS, most of the excitement and expectation centred around those behind him.
Could Ricciardo pass Perez? Could Vettel pass Ricciardo? Could Massa, on fresher tyres and with good straight-line speed, pass all of them?
Without DRS, the answer to each would have been a very simple "no." We'd have been facing up to a five-car procession to the flag with none of the cars involved capable of truly attacking.
Instead, we got a classic.
After two dozen laps stuck in third, Ricciardo overtook Perez for second. Having closed up in the first DRS zone, he took advantage of the Mexican's slow exit from the final chicane to have another DRS-assisted run down the pit straight.
He got by, brilliantly out-braking the Force India on the outside into Turn 1. But he only got close enough because he had the use of DRS and Perez did not.
The Australian went on to pass Rosberg and win the race—this overtake being one of only a handful in the entire grand prix which would have happened without DRS.
Vettel's third place was down to a DRS-assist on the penultimate lap, while Massa and Perez would not have taken each other out had the Brazilian not had the help of DRS to get closer.
There are few things more visually unappealing than a drive-by DRS overtake, the sort of move which is completed hundreds of metres before the braking zone and in which the car being overtaken has zero chance to defend.
When that happens, DRS fails. Unfortunately, we see that sort of pass all the time, and the anti-DRS lobby stock up on some premium ammunition.
But on occasion, the device works as it should. It places an attacking car in the ballpark, close enough to attempt a dive down the inside (or outside), close enough to put a rival under pressure.
Broadly speaking, do you approve of DRS?
Close enough to let one driver use his ability to try to squeeze past and the other to use his ability to make sure he doesn't.
This is what happened in Canada, and it turned a race which would have been a tepid, dreary procession into one of the most breathtaking grands prix of the past decade.
So thank you, DRS. You're as pure as the driven slush and the very embodiment of the word "gimmick."
But you gave us a magnificent Canadian Grand Prix.
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