As a child I was taught that sport should be "sportsmanlike". Perhaps in a situation like this, the real solution should be "I say, it's a draw, well done chaps, you have both proved to be at the top of your field! How remarkable that the result is so close that our best technology cannot even distinguish between the two of you. Well done everyone, what a great race, now let's all go to the pub and celebrate."
This happens in swimming because of the tolerance of making an olympic spec pool. A good swimmer goes a bit over 2mm every 0.001s. The pools have 3cm tolerance meaning the lanes are not the exact same length (it would be crazy expensive to make pools to smaller tolerances)
So to solve this they just don't measure beyond hundreds (no human can swim fast enough that the distance they travel within 0.01s could make a difference). And thus can not use photo finish either as again the lanes are not guaranteed to be the same length.
edit: In other sports like running it is easy to have accurate track length as you just paint the lines after building the track so you can have it as accurate as you want (+photo finish). In swimming it just does not work like that.
> This happens in swimming because of the tolerance of making an olympic spec pool. A good swimmer goes a bit over 2mm every 0.001s. The pools have 3cm tolerance meaning the lanes are not the exact same length (it would be crazy expensive to make pools to smaller tolerances).
It would be crazy expensive to make the pools to such a small tolerance, perhaps, but it is not the length of the pool that actually counts, is it? It is the distance to the touch pad that counts.
Would it be crazy expensive to make the touch pad mounting system adjustable so that the position of each lane's pad could be adjusted to millimeter or even sub-millimeter tolerances?
Main problem is old pools that don't have space for this (would make the pool under length). In general the same rules are used in all levels of competition. The only difference at the moment is minimum pool depth for world championships and olympics which is a bit deeper.
But yes in general new competition pools are built to be slightly larger than 50m and you just adjust the pads at the ends.
You could equalize the length of the lanes, but there are water currents that give different lanes "headwinds" or "tailwinds". These are caused by the pumps, wave action, and thermal convection.
Swimming is worse than that as the inner lanes have inherent advantage of less water drag as the waves bounce off the walls. Of course inner lanes are seeded with the fastest timings from the previous heat.
Exactly- in a few days earlier, Mahe Drysdale of New Zealand won gold in the men's single sculls after being maybe a centimetre ahead of Damir Martin of Croatia at the line:
That still doesn’t guarantee that the winner was the fastest.
Let’s say real times were 58.994999 and 58.995000 seconds. The first gets registered as 58.99, the second as 59.00. Actual difference is a millionth of a second, or, at 2 meters a second, 2μm.
I think they do this in swimming more because swimmers, certainly at shorter distances, more race themselves than their competitors. That’s a huge difference with road cycling, where typically the front riders in a sprint could get over the finish earlier, if they wanted to, but don’t want to do that, as, if they did that, their competition would tail them up to the last few meters and then jump over them.
Rowing is somewhat of a middle ground. They do use finish photos, even though there’s the same. “Tracks aren’t guaranteed to be the same length” problem as in swimming.
I don’t understand why you think it’s easy to have accurate track length in running. Temperature may affect track length. A lot more importantly, I don’t think it’s even doable in events where runners all start in their own track but are allowed to move to the inner track after x meters. But again, it’s less important there because runners race against each other there more than in short swim races.
Rowing alignment is slightly different from swimming alignment.
In swimming, the start and finish are both fixed physical objects that the swimmer must touch (though in all events except backstroke, the start is a bit weird because it's outside the pool).
In rowing, the finish line is an imaginary line much like cycling or running. While at the Olympics there are 'clogs' to hold the bows of the boats which drop down at the start:
a race official is always required to certify that the bows are aligned, which is why the gates are transparent (and the system includes video cameras to help this official).
> “Tracks aren’t guaranteed to be the same length” problem as in swimming.
In rowing you row between 2 imaginary lines. You don't even have to get the distance of these lines perfectly just make sure they are both in the same direction and neither boat gets the advantage.
With swimming you have to build a 50m long and quite wide concrete structure that has straight angles at all 4 corners and has perfectly straight walls. This is actually much harder to do then it sounds.
We could do it in swimming by building the pools a few cm longer, and then having adjustable touchplates to give the precise distance for each lane. :)
This is actually how it is done for new pools. They overbuild them by a couple cm and then adjust the touchplates. But the rules should work for the 50y old pools too.
> You don't even have to get the distance of these lines perfectly just make sure they are both in the same direction and neither boat gets the advantage.
Nitpick: that is not correct. If the shape of the course is a parallellogram, the shortest course between the short sides is perpendicular to those sides. Teams in some of the lanes my be able to pick such a course. For example:
A crew starting in the AB lane can row to D instead. That’s legal, if they don’t hinder other crews. A crew starting at C doesn’t have the option to row a shorter course.
It is very unlikely they won’t hinder other crews if they cross all lanes, but they might just cross lanes of a few much slower boats.
That’s all theoretical, though. The net gain on a normal course would be very, very small, and buoys will typically hinder crews that would try this so much that it wouldn’t be worth it, to start with.
Also, for the true nitpicker, “the right direction” can be difficult. Drawing equidistant lines on a globe isn’t trivial (I don’t think the effect will be large for a 2km course on earth, though)
>Let’s say real times were 58.994999 and 58.995000 seconds.
How do you achieve a million frames per second? Even analog input (like touching - which would be capacitive [hence more tolerances]) will have a very hard time registering that, just based on cable and PCB traces length, temperature differences (which affect silicon and resistance in general). 7 digit precision is a non-trivial task for non-controlled environment. For example 8.5 digit voltmeters take one 1 minute for a single measurement and they have to have extremely good temperature controls.
Then for the microsecond precision you have to consider the speed of sound just to propagate to participants to hear the gun.
They’re not hypothesizing a measurement device recording those times and then rounding. They’re just setting up a “let’s take as a given that this is what really happened in the world” and asking what errors our processes could do if we do a series of imprecise measurements and then compare those measurements.
Side note: my HP 3458A can do a small handful of 8.5 digit DCV measurements per second.
>my HP 3458A can do a small handful of 8.5 digit DCV measurements per second.
I thought they had like 100k samples a second. Is it really sufficient for 8.5 precision?
Edit: perhaps measurement should be confined only to relative finish between the participants, e.g. finish within 1ms should be considered the same (regardless if they fall in the same hundreds of a second bucket)
I don’t keep mine in cal (or even powered up all the time), so I can’t claim full volt-nut status here, but my understanding is the 100K/sec 4.5 digit measurement rate is limited by communications not by sampling rate. (The 5.5 digit rate is 50K/sec, implying the 4.5 digit rate limit is not in the measurement but more likely in the GPIB.)
On thing I know with perfect precision: HP/Keysight knows more than me about this. :)
Well, they could have everyone swim one after another in the same lane. It's not like there's much interaction between racers, as there is eg in a boxing match.
(Of course, this would totally ruin the sport for spectators.
Following this logic, for any sport with no interaction, everyone could just stay home and run around their own track whenever they feel like and just send in their times to a central record keeper.)
Having a competitor next to you provides a stronger absolute result. It's believed to be a standard natural selection/evolution effect. Even pain tolerances increase.
Also conditions change over time. Indoor pools are much less affected than e.g. a ski run in inclement weather or ski flying where competitions are basically lotteries in who gets a favorable gust, but subtle changes in e.g. air oxygen content could easily cause performance differences in the range we are talking about here.
>ski flying where competitions are basically lotteries in who gets a favorable gust
That has always bothered me that there are some calculations/arbitrary numbers based on the wind... to a point the length of the ramp gets adjusted. I recall when the V shape was introduced, initially it was shunned by the judges for bad style (negative points), regardless it was obviously aerodynamically better. However, swimming would also be affected as the water temperature won't be constant either.
I agree that sport should be sportsmanlike, but there is also an entertainment factor. These pro cyclists are public figures, paid by teams funded by corporate sponsors, cyclists have public rivalries and journalists pour fuel on the fire. Events from one race carry over to the next. There is lots of drama, there are rules which change over time (and usually lag a few years behind technology advances), race officials have to make decisions in the heat of the moment, usually very controversial decisions after rule changes. (look at the recent disqualifications due to the new anti-littering and dangerous-bike-position rules this year, and the bike-lane rules a few years ago)
On one side it's unfortunate that technological details and possibly human error make it hard or controversial to decide the winner for this race, on the other side this event has kept the cycling community talking for 3 weeks (even HN is talking about it right now). And most likely in the next few months or years we'll see some rule/regulation changes to handle these cases better. Just like in politics, something needs to happen first before action is taken. All the recent rule changes were triggered by dangerous crashes or other events.
And imho all of this combined makes pro-cycling one of the most exciting forms of entertainment to watch or follow.
A little side note: Many amateur races don't have photo finish equipment. In my race days sometimes not even a camera, and 3 race officials would stand on a little platform above the finish line with voice recorders just calling out jersey numbers and then get together in a room for 20 minutes to compare recordings and compile the final result. Draws were much more common back then.
edit: all of the previous races and media coverage and drama and the first 250k in this race have led to this super exciting final 1k that is ultimately decided by millimeters. To me that is beautiful.
I don't see how declaring this race a draw would deter from the excitement or from the entertainment value. If anything, it would add to it, since this is such a rare occurrence.
Agreed, my response was not meant as a judgement on whether a draw would be a better or worse conclusion. I was trying to highlight the broader context around the events and their outcome.
In this case it wasn't immediately clear who won and the officials had to make a call under pressure with millions of people waiting. They called Van Aert as the winner based on the imperfect data they had. Was it the right call? Maybe, maybe not. In an alternate timeline they might have called Pidcock, or a draw, or a redo of the last 1km.
The takeaway is that this rare occurrence happened and sparked lots of discussion, which hopefully leads to technological and/or regulation changes to could handle these occurrences better in the future. I would call that progress.
> A little side note: Many amateur races don't have photo finish equipment. In my race days sometimes not even a camera, and 3 race officials would stand on a little platform above the finish line with voice recorders just calling out jersey numbers and then get together in a room for 20 minutes to compare recordings and compile the final result. Draws were much more common back then.
Interestingly, technology makes this trivial these days:
Pop a cheap Android phone on a tripod, and with the right software (or even just taking a video), you have a decent approximation of photo finish equipment.
(I say 'trivial', because a smartphones with the required capabilities are basically free, if you take an old, used one.)
Yes indeed. And I have to admit that my race days are more than 10 years ago before smartphones were commonplace. The fancy organizers had camcorders for this purpose, others audio recorders and some others just pen and paper.
About 15 years ago as a teenager I was at a nerdcamp where amongst other things we did lots of physics experiments.
Eg measure how fast bubbles rise in honey at various temperatures to calculate its viscosity. Or: drop various big blobs of water from a height and analyze what happens. Or, figure out at what windspeed candles blow out.
Relatively simple things, but not usually covered in high school physics classes.
Anyway, it was amazing how many experiments became so much more feasible than even a few years prior, because cheap digital cameras were available.
Oh, this also reminds of how ufo and Loch Ness and Yeti sightings have become so much rarer these days, because people demand proof.
Transponders are very common in club level racing now, and the accuracy available is good enough for the grassroots level of competition in pretty much every discipline (except, possibly, track sprint).
Still, I think there will always be a place for a stone-faced commissaire with a clipboard, freezing their ass off in the finish-line rain, watching the bunch draw near.
I worked in this field, posted elsewhere on this page about working photo finish at Amstel Gold in the past. Around that time we also experimented with transponders, maybe even at an Amstel Gold Race, else at the Netherlands Tour (or Eneco Tour). The accuracy, at high speed, of transponders, didn't quite solve for the close finishes. A bigger problem were the practical issues: transponders gone missing in crashes, bike switches, transponders being mounted in the wrong place (enough to matter). It's not a substitute for photo finish. It is, though, a great substitute for reading bib numbers off of a poorly lighted photo finish. They're complementary.
Would you be so kind to provide a short high level summary on how the transponder tech works?
I always assumed the transponders were mostly used for GC timekeeping in multi-day stage races and maybe help automate the initial results shown on TV post-finish.
The live telemetry (wattage, speed, heartrate) we've seen in some races the last few years are also very interesting. But that's probably a different tech stack from transponders used for timekeeping.
Most transponders in competitive sports, and certainly most pro cycling events, will be an active type, i.e. they include their own power source. The timing mats are relatively simple EM trigger loops that induce the transponder to wake up, yelp its identity (typically on UHF frequencies) to the trackside receivers that will actually record the passing time, then go back to sleep. Such systems generally remain reliable even in large passing groups. Commercial prices vary, but the trackside equipment (mat, decoder, laptop, software) typically costs a few thousand dollars, and the transponders ~$100 each with a lifespan of 5 years.
Some manufacturers claim millisecond accuracy, which is plenty for (say) counting laps in cyclo-cross, or for timing many BMX events; but they're not enough to distinguish the places in a >70km/h field sprint for the finish line.
Some mass participation events like public marathons may use low-cost/disposable passive transponders e.g. ones embedded in the bib number; these are more like a typical RFID chip, having a longer (and rather jittery) wake-up time, in part because they draw power from the mat itself, and a much lower transmission energy. They're more easily disrupted by environmental conditions, or when passing in large groups, or even by sweat & skin contact.
Telemetry from onboard bike computers and sensors is indeed a completely separate stack, and can be anything from a bluetooth relay by phone app over cellular, to a dedicated vendor-specific box with its own SIM card and a short-range radio to signal the team car. The onboard sensors are generally using ANT or BTLE to talk to the head unit aka "bike computer" that aggregates, records, displays, and relays the data. Speed may be calculated by GPS/GLONASS/etc, or sensed by wheel rotations e.g. using a spoke magnet or even hub-based rate ticker, in which case the necessary measure of precise wheel diameter may still be calibrated by the head unit using GPS. Power is not measured directly but inferred e.g. by integrating a dynamometer within the crankarm to compute power from strain & cadence. Some units also capture barometric pressure to estimate altitude, and this may be considered more accurate than GPS right up until you ride through a pressure front and it goes bananas. Some bicycles e.g. those with electronic/wireless shifting may also report their current chainring & sprocket selection, and finally you can overlay all this excruciating near-real-time detail onto the Gopro video feed from your handlebars/seatpost cameras and livestream it over cellular networks and thence to the world-wide peanut gallery.
To sum up, there's an awful lot of 2.4GHz activity going on in the pro peloton, and I hereby deny ever having paired a second bike computer with the HR strap and power meter of my nemesis in order to know when the bastard was too tired to follow my attack, no sir
sportsmanlike is when you lose by a hair, you congratulate the winner and don't feel too bad about it. What you're suggesting is a test of competence, not a race.
Or have a tiebreaker. It would be testing something slightly different (more endurance) than what they'd train for, but there would likely be an easier call the second time, statistically if nothing else.
