DRS in F1 explained: the fix that admitted the problem

A driver presses a button, a flap in the rear wing hinges open, and a car that spent four laps unable to get close enough to attack is suddenly alongside on the run to the braking zone. That is the Drag Reduction System. For fifteen seasons, from 2011 to the end of 2025, it was Formula 1's principal answer to the question of how one car passes another.

It was also an apology.

DRS in F1 explained honestly has to start one step before the flap, because the flap is not the interesting part. The interesting part is why a sport that spends hundreds of millions of pounds a year on aerodynamic development needed to bolt a manual override onto its own cars. The answer is that the cars' aerodynamics had made close following so punishing that a quicker car could not stay behind a slower one long enough to attack it. Rather than fix that directly, which is hard, expensive and takes a decade, the sport added a device that gives one car a temporary advantage the other cannot answer.

Every argument about DRS traces back to that origin. The people who hate it are objecting to the artificiality. The people who defend it are pointing at what the racing looked like without it. Both are right, which is why the argument never resolved, and why the 2026 regulations eventually deleted the device while keeping the idea behind it.

The system is worth understanding properly even now that it is gone, because it shaped fifteen years of racing, because it shaped how cars were designed and set up, and because what replaced it inherited its central assumption: that a car within one second of the car ahead should be handed something the car ahead does not get.

• 1Gap that enables it, in seconds
• 2Places on track that decide one activation
• 15Seasons it appeared in the regulations
• 0Cars in a DRS train with a relative advantage

Structural counts rather than measurements. The fifteen seasons run from 2011, when the system was introduced, to the end of 2025, after which the regulations removed it. The final figure is a definition rather than an observation: an advantage granted to every car in a queue is not an advantage over any of them.

DRS in F1 explained, from the flap outwards

A Formula 1 rear wing is an assembly of elements. The lower one, the mainplane, is fixed. The upper one, the flap, was the piece the regulations allowed to move.

An actuator rotates that flap about its pivot so that its trailing edge lifts and the slot between the two elements opens wide. The Technical Regulations specify how far, and the permitted gap was altered more than once over the system's life, so the value that applied in any given season belongs in the published document rather than in a sentence like this one. What matters is the effect. With the flap laid down and the slot yawning, the assembly stops behaving like an aerofoil turning a large mass of air upwards and starts behaving like a pair of plates with a hole between them. The pressure difference across it collapses. Most of the rear wing's downforce disappears.

That is the point. Downforce is not free, and the price is drag. Turning air to make a vertical force also throws a rearward force back at the car, and the rear wing is one of the draggiest devices on it. Dump the downforce and the drag goes with it. The car accelerates harder at the top end and reaches a higher terminal speed for the same power, which is the whole of the mechanism. The arithmetic of that exchange is set out properly in the piece on what a car gives up in a straight line to gain in a corner.

Two details make the device safer and more interesting than the description suggests.

The first is that it closes itself. Touch the brakes and the flap returns to its normal position immediately, without the driver doing anything. The regulations also require the closed position to be the default state, so a loss of hydraulic pressure or a system fault shuts the wing rather than leaving it open. A rear wing that stalled itself into a braking zone would be a serious accident every time it happened, and the failure mode was designed out rather than managed.

The second is that the car with the flap open is not simply a faster car. It is a car with substantially less rear downforce and a balance shifted forwards, travelling at its highest speed of the lap. On a dead straight that costs nothing. In a zone containing a kink, a crest or a corner the driver can nearly take flat, it costs a great deal, and the decision to hold the flap open through a curve that the car can no longer support is a real one taken at speed. Drivers who lift out of it early are not being timid, they are declining to bet the race on a rear end they have just given away.

There is a third-order effect worth knowing. The rear wing does not only make downforce, it lowers the pressure behind the car and helps pull flow through the diffuser, which is explained in the section on the floor in the aerodynamics of a modern Formula 1 car. Open the flap and some of that assistance goes too, so the underbody gives a little back at the same moment. The car loses more than the wing's own contribution.

Why the flap is worth most on the longest straight

The speed advantage is not a number the car is given. It is a rate, and rates have to be added up over time before they become a distance gained.

Open the flap for half a second before the braking board and the chasing car has spent half a second accelerating slightly harder than it otherwise would. That is a few metres, and a few metres is not an overtake. Open it for eight seconds and the car has been accumulating advantage for the whole of that time, compounding as the speed differential grows. The gap closes slowly at first and then quickly, which is why a DRS pass so often looks like nothing is happening and then looks inevitable.

Speed makes it worse, in the useful direction. Drag rises with the square of airspeed, so the absolute quantity of drag being shed by opening the flap is far larger at the end of a long straight than at the start of it. The chasing car is therefore saving the most exactly where the leading car has the least left, because a car near its terminal speed is already spending nearly all of its power on pushing air. Take a slice of that resistance away from one car and not the other and the difference at the end of a kilometre of tarmac is enormous compared with the difference after two hundred metres.

Add the tow, which operates on the same physics from the other direction, and the closing rate at the end of a long straight is the largest speed differential that exists anywhere in a Formula 1 race between two cars neither of which has made a mistake.

That is why activation zones sit on the longest straights, and why circuits without one never produced many DRS passes regardless of how the zones were drawn. It is also why the usable length of a zone is shorter than it looks. The flap has to be closed before the car turns, so the last part of every straight is unavailable, and a zone that ends in a heavy braking area gives back more of itself than one that ends in a fast corner.

One second, measured once, at a place the camera never shows

The eligibility rule is simple enough to state in a sentence and produces most of the system's strangeness.

A timing loop is buried in the track surface at a defined point. This is the detection point. As the two cars cross it, the timing system measures the interval between them. If the chasing car is within one second, it is enabled for the activation zone that follows. If it is 1.01 seconds behind, it is not.

The measurement happens once. It is a sample, not a stream. Nothing that occurs between the detection point and the activation line changes the outcome, in either direction. A driver who is within a second at the loop and then makes a mess of the next corner, dropping two seconds back, still gets the flap and still has nothing useful to do with it. A driver who is a fraction over a second at the loop and then closes right onto the gearbox of the car ahead through the following corners arrives at the activation line with a dark button and watches the car in front pull away.

That second case is the one that produces the most complaint, and it is not a bug. Continuous measurement would be worse, because a driver would gain the wing at an arbitrary instant on a straight and the whole thing would become a lottery of timing. A single sample at a fixed place is at least predictable, and it can be planned around, which is what makes the tactical layer possible at all.

A one-second gap is also not a fixed distance, which is a point almost every explanation of the system skips.

At 100 km/h28m

At 150 km/h42m

At 200 km/h56m

At 250 km/h69m

At 300 km/h83m

Arithmetic, not measurement. A gap quoted in time converts to a distance by multiplying speed by that time, so a one-second interval spans a longer stretch of road the faster the two cars are travelling. Values rounded to the nearest metre. Real circuit speeds vary by corner, by car and by session.

Show the numbers

What a one-second gap is worth in metres

Item	Value
At 100 km/h	28m
At 150 km/h	42m
At 200 km/h	56m
At 250 km/h	69m
At 300 km/h	83m

Put a detection point at the exit of a slow hairpin and one second is a short piece of road, so a car that satisfies the rule is genuinely close. Put it in the middle of a fast section and the same one second stretches to three times that distance, so a car that satisfies the rule may be a long way back in any sense a spectator would recognise. The rule is uniform. What the rule actually asks for is not.

The detection point is a track design decision that decides the racing

Here is the part that gets left out of almost every explanation, and it is the part that matters most. The one-second threshold is fixed and published. The place it is measured is not. Somebody chooses it, circuit by circuit, and that choice decides how many passes the circuit produces.

Consider the geometry. The detection point sits somewhere upstream of the activation line, and the character of the road between them changes everything.

If the detection point sits immediately before the activation zone, with a short and simple link between the two, then a car within a second at the loop is still within roughly a second at the line. The threshold means what it says. The pass has to be earned by closing to within a second and then executing, and the defender has a plausible chance of holding on.

If the detection point sits before a difficult corner where the following car loses time, a car measured at 0.9 seconds may be two seconds back by the time it can use the flap. Eligibility is granted and wasted. Circuits configured this way produce very few DRS passes and a lot of frustrated radio traffic.

If the detection point sits before a section where the chasing car naturally gains, perhaps a corner where the tow helps or where the leading car is limited by tyre temperature, then a car measured at 1.0 seconds arrives at the line half a second behind. The effective threshold is looser than the published one, and the flap is being handed to drivers who had not really closed.

Move that loop three hundred metres either way and the number of overtakes at that circuit changes materially. This is why the locations are revised between seasons, sometimes after a single dull race, and why they appear in the event's race director's notes rather than in the Sporting Regulations themselves. The published rule is a constant. The thing that actually governs the racing is an engineering judgement about where to bury a wire, taken by a small number of people and adjusted by trial and error.

It is worth sitting with that. For fifteen years, the quantity of overtaking at a Formula 1 circuit was set less by the cars, the tyres or the drivers than by the position of a detection loop.

1. 1Outside one second, several corners backThe chasing car is quicker but sitting in disturbed air, losing front downforce in the fast corners and heating its front tyres. Nothing about the system is available yet.
2. 2Building the gap down, over one or more lapsThe driver closes where the car ahead is weakest, usually a slow corner or a traction zone, and manages tyre temperature so there is something left to attack with. This is the part that takes laps and never makes the highlights.
3. 3Crossing the detection pointA timing loop measures the interval between the two cars. Under one second and the chasing car is enabled for the zone that follows. Over it and the lap is spent. The measurement is taken once and is final.
4. 4The link between detection and activationWhatever happens here is irrelevant to eligibility. The chaser may gain or lose. Where this section is long or difficult, eligibility is often granted to a car that can no longer use it.
5. 5Crossing the activation lineThe system arms. A light on the dash tells the driver the button is live. Nothing opens until the driver asks for it.
6. 6The flap opensThe upper rear wing element rotates down, the slot opens, the pressure difference across the wing collapses and most of the rear downforce and its associated drag disappear together.
7. 7Closing rate builds down the straightThe advantage accumulates rather than arriving. The gap shrinks slowly, then quickly, because drag savings are largest at the highest speeds and the leading car has least in hand near its terminal speed.
8. 8The move is committed or abandonedIf the chasing car is alongside before the braking board, the pass is effectively complete and the defender has no answer. If it arrives a length short, the driver has to brake from a car with less rear downforce than usual and the move is normally aborted.
9. 9Brakes applied, flap closes automaticallyThe wing returns to its closed position the instant the driver touches the pedal, restoring rear downforce for the corner. The driver does not have to remember to do it.
10. 10Positions swapped, roles reversedThe overtaking driver is now the defender, and the next detection point will measure the same gap in the opposite direction. On some circuits that is the reason not to have made the pass at all.

The sequence a single overtake follows, from the point at which the chasing driver is not yet eligible to the point at which the move is finished. Every step is a decision or a measurement, which is why two cars with identical pace can produce this sequence on one lap and not on the next.

Why some circuits carry more than one zone

One zone works where one long straight ends in a heavy braking area and the circuit does the rest. Plenty of circuits are not like that.

The response was to add zones. A second activation zone gives a chasing driver a second attempt on the same lap, and the arrangement of detection points around those zones is where the design gets subtle.

Two zones can share a single detection point. A driver measured within a second once is then enabled for both, which means a failed attack in the first zone is followed immediately by another go in the second. This produces a great many passes and a certain amount of criticism, because the chaser gets two swings for one measurement while the defender gets no opportunity to reset the situation in between.

Or each zone can have its own detection point. Then the pass has to be earned twice, and completing an overtake in the first zone hands the newly overtaken driver a measurement of their own before the second. That configuration produces fewer passes and better ones, and it creates the tactical situation described further down, where the correct move is sometimes not to overtake.

Zone counts per circuit changed from season to season and are published in the event documents rather than fixed anywhere permanent, so the number at any given track is a thing to look up rather than a thing to remember. What is stable is the reasoning: zones are added where the circuit does not generate passes on its own, and the sport reached for more of them whenever a race was dull, which over time meant the medicine kept being increased rather than reconsidered.

There is a failure mode at the other end. At a circuit where the tow alone would have been enough to set up a move, adding a long zone makes the pass automatic, and a pass that cannot be defended is not much more interesting than a pass that cannot be attempted. The two cars simply exchange places on alternate laps until one of them pits. Too much of the aid is as unsatisfying as too little, and finding the middle is a per-circuit problem with no general solution.

When race control takes it away

The system was never continuously available, and the exceptions are more revealing than the rule.

The opening laps. DRS is not enabled for the first laps of a race, nor for the laps immediately following a restart after a safety car or a red flag. The lap count is set out in the Sporting Regulations. The reasoning is practical: at a standing start and at a restart the field is compressed, so almost every car is within a second of the one ahead and the aid would be universal and therefore pointless, and a pack of cars on cold tyres opening their rear wings simultaneously is a bad idea on its own merits. The interaction between restarts and the aid is one of several reasons the rules governing a safety car period matter more to a race result than they look like they should.

Wet or dangerous conditions. Race control suspends the system when the track is wet enough that opening the wing is unsafe, and restores it when the track improves. Two things are going on. Removing rear downforce on a low-grip surface takes away the grip the driver most needs, at the highest speed on the lap. And in heavy spray a driver cannot see the car ahead well enough to judge a closing rate, which turns a fast approach into a guess. The decision belongs to the race director and is communicated through the official messaging system, which is why a race in changing conditions has the aid coming and going.

A single zone, rather than all of them. Race control can disable one activation zone and leave the others live. Debris on that part of the circuit, a damp patch that has not dried with the rest of the track, or an incident nearby are all reasons. Yellow flags in a zone remove it for as long as they fly.

Qualifying and practice. In those sessions the proximity rule does not apply. Every car may use the zones on every lap, which has a consequence people rarely connect to it: qualifying pace is set with the aid always available and race pace is set with it usually unavailable, so the two sessions are not measuring the same car. This is part of why a car that qualifies well can look ordinary on Sunday, and it feeds directly into how teams approach the format of a Formula 1 qualifying session.

The strategy in DRS, explained by drivers who slow down on purpose

Once you accept that eligibility is decided at a fixed point rather than continuously, a genuine tactical game appears, and it is the best thing about the system.

A chasing driver knows where the detection point is. If the gap is hovering around a second, the sensible play is to shape the lap around that one place: sacrifice a tenth in a sector that does not matter, use the tyres somewhere cheap, and arrive at the loop within the threshold even at the cost of being slower elsewhere. A driver who does this well converts a marginal gap into eligibility on lap after lap, and a driver who does it badly spends a whole stint at 1.05 seconds, close enough to ruin their tyres and never close enough to attack.

The defender plays the same game inverted. The lap is not one lap, it is one sprint into the detection point and then whatever is left. Pushing hard in the sector before the loop, even at a cost in tyre life that will be paid later, buys immunity for the next straight. Defensive driving under DRS was rarely about the corner where the pass happens. It was about a piece of track some distance earlier that television almost never showed.

Then there is the move nobody understands until it is pointed out. At a circuit with two zones and a detection point before each, being ahead at the second measurement is a liability. A driver who completes a pass in the first zone becomes the defender before the second detection point, hands the flap to the car they have just passed, and gets re-passed on the next straight. The correct play is often to close, decline the move, sit within a second, be measured, and use the second zone to make a pass that cannot be answered before the lap ends.

So a driver deliberately fails to overtake. On television it reads as a failed attack or a lack of nerve. It is neither.

1. 1Approaching the first detection point, within a secondEligibility for the first zone is secured. The driver now has a choice to make before the straight, not during it.
2. 2Question one, is the pass available at all?If the closing rate will not bring the car alongside before the braking board, the question answers itself and the lap becomes about tyre management instead.
3. 3Question two, where is the next detection point?If it sits after the first zone, completing the pass now means being measured as the defender within seconds. That reverses the advantage before the lap is over.
4. 4Question three, can the position be held without the aid?Fast circuit sections, a tyre advantage or a car with better traction out of the corners may make the position defensible. On a power circuit against a car with a tow, it usually is not.
5. 5Option A, take the pass in the first zoneClean, immediate, and vulnerable. It works when the following section is defensible or when the second zone is short enough not to matter.
6. 6Option B, stay behind and be measured againThe driver holds station, stays inside a second at the second detection point, and takes the second zone instead. The pass then lands with less road left for a reply.
7. 7The cost of Option BAnother straight spent in disturbed air, more heat into the front tyres, and the risk that a third car arrives and the whole situation changes. Declining a pass is never free.
8. 8What it looks like from outsideA driver who could have gone past and did not. Almost always a calculation about the next measurement rather than hesitation.

The reasoning a chasing driver works through when a second measurement sits between the two activation zones. The conclusion depends entirely on where the detection points are placed, which is why the same driver plays this differently at different circuits.

There is one arbitrary edge to all of this that no amount of clever driving fixes. The measurement is taken against whichever car is directly ahead, whatever position it is in. A leader catching a lapped car is measured against that lapped car and gets the flap. A driver defending a position who happens to be closing on a backmarker gets the flap too, and their own attacker, measured against them, gets it as well, so the fight is briefly conducted with both cars' wings open and nothing changes. Traffic makes the system incoherent in a way that has nothing to do with the merits of either driver.

What DRS quietly did to car design

The device changed more than the racing, and this is the part almost never discussed.

If a car can dump most of its rear wing drag on the straights, the penalty for running a large rear wing falls. Teams could carry more downforce than the circuit's straights would otherwise justify, because a share of the cost was refundable in qualifying, where the aid was unconditional, and recoverable in attack, where it was not. That pushed setup choices towards more wing across the calendar and made the cars quicker in corners and slower in a straight line than they would have been under the same rules without the device.

Which made following harder. A car with more downforce sheds a stronger wake and depends more on clean air, so the aid designed to compensate for the difficulty of following made the difficulty of following slightly worse. That is not a large effect compared with the underlying aerodynamic problem, and no team would say it drove their programme. It is, though, exactly the kind of second-order feedback that appears whenever a sport patches a symptom, and it is the reason the debate never stayed settled.

The honest case against, and the honest case for

Against, and none of these is unreasonable.

It produces passes that are not really overtakes. When the closing rate is large enough that the move is complete before the braking zone, the defending driver has no move available. A late brake, a defensive line, a dummy, all of the craft that makes a genuine overtake worth watching, is irrelevant to an outcome decided by a rule. The pass is executed on the defender rather than against them.

It is asymmetric by regulation rather than by merit, and the sport applies that principle nowhere else. Nobody suggests giving the second-placed car more fuel flow. The one place it was accepted was the one place the sport had a problem it could not otherwise solve.

It devalues defending as a discipline. A driver who is brilliant at holding a faster car behind, historically one of the most admired skills in racing, was placed in a category of one against a stopwatch.

And it let the regulators off. A visible patch reduces the pressure to fix the underlying failure, because the racing looks acceptable while the cause goes untreated. Fifteen seasons is a long time to run a temporary measure.

For, and this is the part the critics tend not to engage with.

The alternative was not purer racing. It was a procession. A car with a clear pace advantage would sit behind a slower one for an entire stint, unable to follow closely enough through the corners to arrive at the braking zone with any speed in hand, its front tyres cooking as it tried. The full mechanism of why following ruins a car is set out in what dirty air does to a chasing car, and it is not a small effect that a determined driver can overcome with commitment.

A pass that looks easy is frequently the end of ten laps of work. The system does not hand a driver the gap, it converts a gap the driver built. Getting from three seconds to one, and staying there without destroying the front tyres, is most of the job. The flap is the last four hundred metres of it.

It is transparent, uniform and applied identically to everyone, which is more than can be said for many of the ways racing sorts itself out. And it is cheap. Redesigning circuits to generate overtaking is slow and enormously expensive, and rewriting the technical rules to fix the wake takes a decade and gets partly undone by the teams within three seasons of being introduced.

Did the ground-effect rules reduce the need for it?

The 2022 regulations were the serious attempt at the underlying problem. Downforce was moved downwards, from wings and upper bodywork onto a shaped underfloor, because a car that takes its performance from the floor is less sensitive to the quality of the air arriving at the front of it. The wake itself was reshaped, with outwash suppressed and the rear wing profiled to throw the disturbed air upwards into a narrow plume rather than outwards into a broad sheet. The reasoning is set out at length in the piece on how a modern venturi floor works.

It worked, partially, and then it eroded.

Following at close quarters did become easier. Drivers said so, and the sport's own targets for how much downforce a following car should retain were written into the rules and largely met at the start of the cycle. Yet a rule cycle is not a static thing. Teams recover performance wherever the regulations leave room, and outwash is one of the fastest routes to lap time available. The front wing endplates and floor edges of a mature rule cycle do not look like the ones from its first season, and they do not behave like them either. The wake got dirtier as the cars got quicker.

Two other choices in the same package pushed the other way. The cars were made heavier and wider, and both make overtaking harder for reasons that have nothing to do with air. A heavier car brakes later and takes longer to change direction. A wider car needs more road to sit alongside another one. The aerodynamic gain was real and it was partly spent on mass and dimensions.

The decisive evidence is what the rule-makers did rather than what they said. They wrote regulations explicitly designed to reduce the need for an artificial overtaking aid, and then retained the artificial overtaking aid for the entire cycle. Nobody proposed removing it as a test. That is not the behaviour of people who believed the problem had been solved.

The 2026 rules deleted DRS and kept its logic

From 2026 the Drag Reduction System is no longer in the regulations. It is worth being precise about what replaced it, because the two changes are often described as one thing and they are not.

The first is active aerodynamics, which is available to every car all the time. The wings move between a high-downforce configuration for corners and a low-drag configuration for straights, in sections of the circuit designated for it. Every driver gets this. It is not conditional on position, it is not a reward for being behind, and it is best understood as a technical solution to a technical problem: cars that carry the downforce they need where they need it and shed it where they do not, rather than dragging a fixed compromise around the whole lap. In that sense it is what DRS would have been if the sport had designed it as engineering rather than as a remedy.

The second is a separate overtaking aid, and this is where the inheritance shows. A driver within one second of the car ahead is permitted an additional deployment of electrical energy, which the regulations described as a manual override and which the sport renamed for broadcast. The mechanism moved from bodywork to the power unit, tying the whole question to how a modern Formula 1 power unit deploys and recovers energy, and the advantage is now a burst of power rather than a reduction in drag.

Look at the condition, though. One second. Measured against the car ahead. Granted to the chaser and not the defender.

The sport removed the flap and kept the crutch. Whatever else changed, the underlying admission did not: Formula 1 still does not believe its cars can be raced closely without giving the car behind something the car in front does not have. That is the honest summary of the 2026 change, and it is a more interesting fact about the sport than any figure attached to the new system.

Since these rules are new and were adjusted during their introduction, the current wording of the proximity condition, the energy limits and the designated sections belongs in the published Sporting and Technical Regulations rather than in an article, and the FIA's documents portal is where to check it.

What a sport should do when its own rules break its racing

DRS is a case study in a problem every rule-based sport eventually faces. The rules produced an outcome nobody wanted. What now?

There are three responses and Formula 1 has used all of them, in the wrong order.

The first is to treat the symptom. Add a device, a bonus, a handicap, something that restores the appearance of what the sport is supposed to look like. It is fast, it is cheap, and it works immediately. It also anaesthetises the pressure to do anything else, and temporary measures have a way of becoming permanent because removing them means accepting a visible step backwards. Fifteen seasons.

The second is to fix the cause. Rewrite the technical rules so the cars can race each other. This is slow, expensive and uncertain, and its effects decay, because the competitors will spend every hour they have unpicking whatever the regulations tried to achieve. It is still the only response that addresses the actual failure, and the 2022 rules deserve credit for being a genuine attempt at it rather than another patch.

The third is to accept the outcome and change what the sport rewards. If following closely is hard, then perhaps the competition should be more about strategy, tyre management and track position, and less about wheel-to-wheel passing. Formula 1 has never seriously considered this, and it is right not to, because passing is the thing people came for. It is a legitimate answer all the same, and other sports have taken it.

The specific lesson from DRS is about ordering. A patch applied while the cause is being fixed is a reasonable piece of governance. A patch applied instead of fixing the cause becomes the sport. The distinction lies entirely in whether the temporary measure has an expiry attached to it at the moment it is introduced, and DRS never did. The same pattern runs through most of the regulatory history covered in the rest of the motorsport writing here, from engine freezes to spending controls: a measure introduced to buy time, and then never given back.

Watching a DRS train

The clearest single image of what the system was, and the best place to end, is the queue.

Five or six cars, nose to tail, each one within a second of the car ahead at every detection point on the lap. Every one of them is enabled. Every one of them opens the flap at the same activation line, at the same moment, and every one of them shortens the gap to the car ahead by exactly the amount the car behind is shortening the gap to them. Nothing moves. The whole train is going faster than any of the cars would alone, dragging less, thundering down the straight in perfect formation, and no car in it can pass another.

An advantage granted to everybody is not an advantage. The train holds until somebody pits, or somebody's tyres finally go, or a car ahead of the queue makes a mistake and the front of it breaks up. Until then it is a demonstration, at three hundred kilometres an hour, of a fix that only works if it is scarce.

If you are watching a race and want to see the system rather than the result, four things repay attention.

Watch the sector before the detection point, not the straight. That is where the fight is actually taking place. A defender putting in a suspiciously quick sector and then appearing to fade is buying the next straight. A chaser losing time in an odd place is often positioning for the loop.

Watch for the driver who does not go past. A car that pulls alongside, holds there, and then tucks back in has usually made a decision about the next detection point. Look for a second zone later in the lap.

Watch the closing rate rather than the gap. A car that gains a length a second is going to make the move. A car that gains half a length over the whole straight is going to arrive short, have to brake with less rear downforce than it wants, and lose more in the corner than it gained on the straight. Experienced drivers know which one they are in before the halfway board.

Watch what a car does the lap after it gets clear. The lap time a driver produces immediately after breaking free of traffic is the honest measure of what following was costing them, and of how much of the pass the flap was actually responsible for.

The question worth asking of any DRS pass was never whether it was artificial. It obviously was. The question is whether the driver had built a gap worth converting, and whether the position of one buried wire, chosen by a committee, gave them the chance to convert it or handed it to them.