There is another plausible explanation: there are many people, especially photographers, near the turn for lanes 1-4 but none for 5-8. The start has people on both sides. The rest of the deck is barren. Even after 15 years of competitive swimming, the visual presence of yelling people still had impact on my effort level, while the presence of a stroke & turn judge leads to a tightening of form (ie less dolphin kick in breaststroke).
Edit: of course, this could still be unfair but at least it would be due to human psyche rather than currents
Another idea: many of the swimmers breathe only to one side (in the races that they breathe at all), so in one direction they would be able to (better) see the faster swimmers towards the center. Another possible psychological factor.
That's something to check, but seems unlikely. The effect is noticeable in freestyle, where it's kinda hard to DQ, and there's a judge in every lane (iirc), so there's no reason to slow down.
The graphs make the effect look pretty linear, which doesn't fit with my model of sports psych. Shouldn't there also be a slight bump for lanes 7 and 8, because they're also closer to the smaller crowd on that side? Instead it's a straight slope straight across the pool. Is the inspiration boost that comes from moving from lane 2 to lane 1 equivalent to the boost from moving from 8 to 7? I'd expect some inverse square law to apply.
This is what the announcers speculated was happening during Ledecky's 800 freestyle heat, as they noticed she was swimming faster splits in one direction than the other.
It should be easy to check if the results are more or less skewed for back, breast, and fly events, where most swimmers do not favor a particular side.
That's certainly a good data point in the 'against' column, but it really only indicates that any current, if present, isn't likely to be caused by the normal circulation of water from filtration systems or similar. There are a number of other things that could possibly be causing a current.
For instance the current could be caused by the interaction between the pool and the motion of the swimmers in the pool. It could be caused by the overflow wave from 8 people entering the pool. It could be caused by uneven gutter heights leading to the pool draining at a faster rate on one side/corner. It could be a combination of all of these things, none of which would show up in a static test like the one they demonstrated.
The fact that this has happened at some races and not others, and the ones it looks like it has happened at are Myrtha pools, is interesting in itself.
Those tests are with floats. That may be the standard but it isn't appropriate imho. Swimmers do not swim in the top few inches of water. They swim as deep as four feet in dives, and are constantly dipping hands feet down two or more feet. Any current down there would go undetected by such a float, especially when it is surrounded by lane ropes.
Do a test with something hanging below the float, below the protection of the lane ropes. Or drop some dye in the water.
(I'm a little surprise by the wave action visible in these tests. With so many ropes, that water should be like glass very quickly.)
There is some theatre here. Swimmers know the water moves, that it isn't a stationary tank. A perfect pool, with perfectly still water in every lane during an actual race, isn't possible. As slight winds can affect football games, swimmers just have to live with slight inconsistencies between lanes and pools.
Take this from a former competitive swimmer (a not-slow one) now with 25+ years of lap swimming: This is far more complicated than the OP.
Reasons for a current:
(1) This is an outdoor pool. Sunlight is the death of chlorine in pools. The bigger the pool, the brighter the sun, the more chlorine is burnt off. The chlorine-related chemicals used in pools also do not properly dissolve in water. They slowly rise towards the surface. So when you turn off the circulation system, they rise towards that deadly sunlight. Given that, and the fact that they were having epic chlorine-related problems, it is of no surprise that they would have run the circulation systems as much as possible when the pool was not in use. But pool water doesn't stop instantly. A gyre may have formed and be stable for hours afterwards. Laneropes are meant to stop this, but they do little under the surface.
(2) This is an outdoor pool, in direct sunlight, with the pumps off during the day ---> convection currents. And the circulation system is off. This is most interesting because as the sun rises one would expect an asymmetric current to form based on which side of the pool got the most sun. Normally this would be, in the southern hemisphere, the south west corner. I would expect an upwelling there along the wall, with a much lesser current across the pool surface from SW to NE.
Effects of the current.
Head/tailwinds aren't normally an issue. The faster one swims the lesser the effect. If this were happening we would see it in differences between length splits (fyi "length"=50m and "lap"=100m, many confuse those terms). I think up/down-welling currents are more at play. Fast swimmers rely on very specific stroke patterns. Slight perturbations in the water can throw off a swimmer's stroke. Imagine swimming past a water jet or upwelling and your hand is pushed sideways. That can slow you down far more than fighting a slight current.
If I am correct, the greatest effect would be in the SW corner of the pool. Anyone know which lane that would be? In the footage, we should also see swimmers drifting (both left and right) when approaching that SW corner.
See those windows. This is an outdoor pool under a temporary structure. Sunlight (UV) is coming in and air is circulating. And if the the pumps are running, they aren't at full power during races. Often at such events officials will state that pumps are run when they are in fact off. This is a common conflict between the needs of the event (stable water) and local health codes that dictate that circulation pumps remain on. In a 50m pool, if they are on they aren't 'on' enough to keep things mixed.
That seems pretty damning to me personally, but I'm not a statistician. It's also something I would never think could give an advantage, but I guess it makes sense that it would, especially with some of these finishes that are within tenths of a second.
Wouldn't be surprising either, the Rio Olympics as a whole seem to be a mess, and I doubt most pool builders even consider it.
Not sure why Diego is being downvoted so much, when parent who made an equally incendiary comment wasn't.
Many respected "first world" journalists have also commented on the same pattern of people from richer countries condescending to poorer countries that host the Olympics.
Black September attacking the Olympic village was a less predictable event than many of the problems occurring in Rio, like chlorinating the diving pool with the wrong chemicals.
This is plain and simple prejudice and bullshit. The government has been following thru on commitments.
* When Rio was announced people said the venues wouldn't be ready on time. They were.
* When zika broke out people predicted an Olympic pandemic. Then came southern hemisphere winter and you're more likely to get zika in Florida than Rio.
* When media discovered pollution in Guanabara Bay people asked for cancellation of events out of health concerns. No event was cancelled and no evidence of health hazards.
* when a chemical imbalance turned a swimming pool green people called for cancellation. It turned out to be harmless algae.
* when American swimmers claimed to be robbed a media uproar denounced a security chaos. Turns out they lied to hide a visit to a brothel.
All of this is a continuation of a pattern. Rich countries freaked out with the Olympics in Beijing and Sochi too. Rio would have to endure the same.
> * when American swimmers claimed to be robbed a media uproar denounced a security chaos. Turns out they lied to hide a visit to a brothel.
Do you have a reference for this? I'm aware of the inconsistencies with the stories in this situation, but I've never seen a brothel mentioned anywhere.
And Brazilians continue to boo foreign athletes. To the point of tears. As a nation of sports fans and as hosts, that is the face they choose to show the world: booing their guests in athletic competition.
Booing happens everywhere. A lot of the people complaining on reddit are Americans, and American sports are quite partisan. Elite athletes competing for silver at the Olympics should be able to handle booing.
Maybe, they should be able to handle some booing. Doesn't make it appropriate behaviour to force them to go through it, as hosts. It's an event whose entire premise is to rise above partisanship in the name of sportsmanship, we can expect a little more sportsmanship from the crowds too.
Nobody is forcing anyone to go through it (except North Korea maybe?). If an athlete cannot handle the booing, he is welcome to skip the Olympics. I agree that the whole thing would be so much better if the crowds were nice, but it is what it is.
I didn't mean parent countries were forcing their athletes, I meant Brazil, as the host, are not living up to reasonable expectations on hosts of an international sporting event. You say it as if all athletes were given due notice, and agreed that they would take racist, partisan abuse. The crowds are uniquely, surprisingly bad. The answer to this isn't "you're welcome to leave", that does not deflect blame from the way Brazilians have been behaving. And just saying "it is what it is" downplays just how far below basic standards of decency such booing is.
So pretty much the same as US Open and Wimbledon for example when US or UK is competing against foreign players? Or French Open? I can go on if you want...
Booing is not something invented and exclusive to third world countries or Brazil for that matter.
Not actually American or British, not sure why you assume I must be western first world and accuse me of hypocrisy based on that.
In any case, that fact that booing has happened in previous events I can accept, but that seems a false equivalence. I'm pointing out that to my knowledge, this is the first time it has happened with such vigour and insistence at a world wide sporting event. What is the point of the Olympics if not to overcome partisanship in the name of good sportsmanship? A lot of the Brazilian fans' behaviour seems to come from the worst of futbol hooliganism, which no-one could seriously defend, and their booing of Argentinians in particular shows an unwillingness to rise above regional rivalries even for the Olympics.
Even Olympics officials have said the conduct of the Brazilian fans is unacceptable. If you're not just trolling you can search out some quotes yourself.
Olympics officials does not equal "international". But please do show me that international condemnation of Brazilian fans. Or is 2% of the world considered international and only right and righteous today? I already know the answer but do go ahead.
I find it quite disturbing accusing Brazilians of "booing" at sports event when you could and can see this in events such as US Open, Wimbledon and other "clean and gentlemany" sports when the opponent is from some other country than US or UK. Let's not get into more "dirtier" sports now where booing is de facto standard.
I think there are a lot of differences here in terms of the level of blatant corruption, extreme disrespect shown by the Brazilian fans, insane crime reports, Zika, etc.
There's a reason the /r/apocalympics subteddit is so popular.
I'm no expert, but it seems to me that the booing is mostly down to different cultural expectations (i.e. Brazilians don't necessarily see it as disrespectful):
50 m freestyle final. Manaudou, defending champion, came second to Ervin (previously gold medalist in the event) by 0.01. Ervin was in a more favorable lane according to the data (in 3 against Manaudou's 4). In such a short distance, the tiniest advantage becomes massive!
The feeling of messiness is generated by the vapid NBC coverage. The coverage of sports is so poor, I imagine that other, non-core coverage is garbage as well.
Fantastic analysis. One important question not covered in the article: how are lanes assigend in swimming? In rowing we have a qualification system that is geared to have the best crews start in the middle two of the 6 lanes, then going further out. For all I know about fluid dynamics, swimming in the outer lanes should have a disadvantage (swimming close to the pools boundary adds drag).
Lanes in swimming are according to speed. If you have the fastest prelim time, you're in lane 4. Second fastest in lane 5, then continuing down to 3,6,2,7,1,8. As for the boundary stuff, at the top meets, they don't have a swimmer in the lanes closest to the wall (https://www.youtube.com/watch?v=GXC4hYnH4n0).
Wow, that is a tiny tiny pool. It's fine for kids, but seeing competitive swimmers racing across 25 yards is just funny. The doubled-up, yet still tiny lane ropes are also cute.
Finals are seeded 4,5,3,6,2,7,1,8 fastest-to-slowest.
Semifinals are circle seeded (two heats where b is the second heat) 4-b, 4-a, 5-b, 5-a, 3-b, 3-a etc.
Heats are circle seeded for the last (fastest) three heats, and then regular-seeded for the remaining heats.
Basically if the pool had a current, you'd expect to see more 'upsets' from the lanes with less current, or from the lanes with a positive current in the case of the 50m.
Note that, while there is a common perception among athletes that the middle lanes are advantageous (or at the least, preferable), there is not backed up by any scientific evidence:
Swimming immediately next to the wall, as in inches from it, can also have advantages. The fastest way of getting from one side of a pool to another is dolphin kicking along the bottom. The water coming off your stroke pushes against the solid surface, effectively giving you more 'grip' than you would have in open water.
In swimming your lane is determined by your seed time. In events with multiple heats it gets more complex, but the fastest people are in the middle lanes.
The stats look really damning. Notice the p-scores : 4e-19 for worlds 2013 and 5e-8 for olympics 2016. And you can see it so clearly in the graphs too. No question, there was a big difference between one side of the pool and the other!
The p values don't necessarily imply what you think they do. The p value you end up with is a function of the modeling assumptions you make. For example, if your errors are correlated (which I'm sure they are in these swim meets since many data points can correspond to the same swimmer and many are from the same race), then you need to account for that. It's not uncommon to have a p value like that, then you account for something you forgot and it goes away.
Those aren't the stats that really matter though. At the end of the day, the question isn't whether the pool is fair or not, but whether the people watching the event on TV still go out and eat McDonalds or whatever afterwards.
Most sports aren't really 'fair' per se. Making them fair wouldn't be cost effective, and wouldn't make for good TV. E.g. everyone knows that some lanes are faster than others in rowing due to the lack of wind screens around the venues. And that's not even to mention the people who spend ten years training only to get violently ill and unable to compete due to the water quality. The reality is that even at the highest levels of competition there is still a lot of luck.
> The reality is that even at the highest levels of competition there is still a lot of luck.
It really depends on the sport. For instance, football (soccer) is very random, and this is amplified by the tournament format. But in many other sports, there is no suspens at all. Actually, it would be interesting to somehow evaluate the random factor for each sport.
Some even argue that the randomness of football (which Americans know by riddiculous name "soccer") is the main factor that makes it the single most popular sport in the world. Some unlucky events end up being remembered for generations.
For example people in Poland are still discussing over the beer whether we would have been world champions if only it hasn't been raining so heaviliy during Poland - West Germany semi-final in 1974.
P.S English is not my language and I'm pretty sure I messed up with conditionals, hope you still get what I meant in the last sentence.
The name “soccer” is just an old British slang abbreviation of “Association Football”, to differentiate it from other kinds of football (that is, games played on foot, as opposed to horseback—compare “footrace”). You can find old references to “Rugby football” and “rugger” as well. Americans kept the term, Brits didn’t.
Exactly. And America isn't the only country that kept the abbreviation. Australia, Ireland, Canada and some countries in Southern Africa use the same term.
> P.S English is not my language and I'm pretty sure I messed up with conditionals, hope you still get what I meant in the last sentence.
Change "hasn't" to "hadn't" and your conditional is perfect.
(If you're curious, you've made what I would consider a definiteness error three times -- I would say 'the ridiculous name "soccer"', 'discussing over beer', and 'the Poland - West Germany semi-final in 1974'. Those won't affect understanding and you give the impression of being very fluent; there are no other errors.)
For sports are head-to-head match-ups with scores, and have leagues with sufficient games per season, you can evaluate the amount that luck is involved by comparing the points-scored/points-allowed to win/loss over a season.
Merely empirically determine the appropriate exponent to input for the pythagorean win percentage[1]. Baseball uses an exponent slightly under 2, while basketball uses an exponent slightly under 14. The higher the exponent, the less likely a poor team is to defeat a good team.
In fact this can be generalized to sports without points if you have some other way of estimating a team/player's "quality" normalized to 1 being "average" which is all the points-scored/points-allowed ratio does.
[edit]
Note that the Jamesian (points-scored/points-allowed) quality metric doesn't work as well in games where draws are common (e.g. soccer/football), and different quality metrics will yield different exponents, so do not allow apples-to-apples comparisons. For what it's worth, applying James's quality metric to league football yields an exponent of about 1.3[2], which is in line with the intuition of ranking these 3 sports from most to least luck per win:
Even in sports with less variance in performance (e.g. weightlifting), we're only looking at one or very few data points. There are definitely random factors in the final outcome, but it may even add excitement to the events.
That said, I still think fairness or at least perception of reasonable fairness is very important in high-level sports. No one is going to watch the games (or the ads as the GP pointed out) if they think the game's rigged.
Oversimplifying it a bit. Imagine a swimmer swims 5m/s and the current adds/subtracts 1m/s. The pool is 50m. No current each length should take 10s. Going with the current takes 8.3s and going against the current takes 12.5 seconds. 100m takes 20.8s instead of 20s. Why?
While the benefit/detriment ratio is 50-50 in terms of distance, it's not 50-50 in terms of time. You spend less time benefiting from the current because you are going faster.
Alternatively, if the race was a fixed 10seconds in each direction you would go 60m and 40m, making it equivalent.
Yes. Imagine a current flowing exactly as fast as you can swim and you must swim one lap with it and one against it. You cover the lap in half your normal time when it's helping you and then when it's against you you cannot _even_ cover a lap. Total time = infinity.
>you must swim one lap with it and one against it.
Lengths, not laps. A lap in running brings the runner around the track and back to where they started. A lap in swimming is from one side to the other and back again (100m). A length, from one side of the pool to the other, is 50m or half of a lap. If there is a current one length is different from another other, but the laps are identical.
If you look closely at the data, the effect was stronger in lanes 1 and 8, and weakest in lanes 4 and 5, which implies that the current was circular. This means that those in the outside lanes would get a bigger boost than those in the inside lanes.
Even with a circular current, there would be effects that don’t even out over the course of a long race. These add up to a few tenths of a second for the swimmers in the outer lanes of the 800 and the 1500. In a race that was decided by seconds, this would not have affected the final result ordering. But in a 50, a difference of a couple tenths of a second due to a push or a pull could be the difference between a medal and not.
I few tenths of a second over 800 or 1500 meters should be (a few tenths of a second) / (800/50) or (a few tenths of a second) / (1500/50) when scaling it to the much smaller 50m, should it not? A few hundredths of a second, or even a few thousandths of a second, given that there's an order of magnitude difference.
I think they were saying that many of the effects cancel out over multiple lengths, as you're slowed down one way and sped up the other. It's not a perfect cancellation but it does diminish the problem.
However the 50m is just one way, so you get the entire effect with nothing cancelling it out at all. There's also then a much bigger difference between lane 1 and 8.
If everyone did two lengths, then lanes 1 and 8 would have been penalised a bit (faster one way, slower the other) but they'd have done the same as each other. Lanes 4&5 would have been a bit better.
Now picture just one length. Lane 1 never has to swim against the current, while lane 8 has to fight it all the way.
I agree with your reasoning about how it could affect a one way race, but if that was actually the intention of the referenced portion of the article, I think they went about it in a very confusing manner at best.
I was puzzling over exactly this during Ledecky's win in the 800m. I watched a replay with constant WR graphic overlay, so you could see her gaining and losing ground on it. IIRC the BBC commentators also contradicted themselves more than once about whether she was going even better or about the same (without really realising something strange was going on).
One really doubts they have good enough records to accurately draw that line. More probably they're just moving it at a generally constant speed, fudging a bit at the turns.
The amount of dilemmas surrounding Rio 2016 is staggering. From polluted rivers that leave rowers sick to muggings and now this: poorly designed swimming pools?
NY Times reports that the "public officer" (actually an off duty prison guard) did brandish a gun, and demanded money. Vandalism or not, that's precisely the definition of armed robbery.
Lochte certainly lied about the details, but two wrongs don't make a right, and only one of these wrongs carries up to a 20 year sentence with a 5 year minimum, at least in the US.
Edit: of course, this could still be unfair but at least it would be due to human psyche rather than currents