Is a 'slow' swimming pool impeding world records? • Hacker News Board

Re: Is a 'slow' swimming pool impeding world records?

#251

Post by Scarblac » Thu, Aug 01, 2024, 6:54 AM UTC

bitmasher9 wrote: post #152

beloch wrote: post #148

Earlier quoted context omitted.

It's hard to control conditions for a Marathon, but what's to stop some future Olympic host from intentionally creating the fastest pool possible that wouldn't be objected to, just so they could watch "their" Olympics break all the records?

Don’t we want Olympic hosts to create optimal conditions for athletes to demonstrate their skills?

We want Olympic host cities not to go into billions of debt that they'll never make back, as that will make it hard to find good hosts. Paris tried to be prudent tinancially.

Re: Is a 'slow' swimming pool impeding world records?

#252

Post by lordnacho » Thu, Aug 01, 2024, 6:54 AM UTC

thaumasiotes wrote: post #239

conductr wrote: post #153

Earlier quoted context omitted.

My untrained eye has noticed. But I also think it's not really a big deal. There are so few events where the conditions are exactly the same every 4 years. Just kinda the luck of the draw if you happen to be competing in the most ideal conditions for WR setting in any event

> There are so few events where the conditions are exactly the same every 4 years. The Olympics used to be held at Olympia. It's not difficult to make the conditions the same every four years.

On that note, I should mention the idea of having a permanent Olympic city. Perhaps a new one.

That way, there's no circus that goes around at great expense each time, and the Olympic city becomes a centre for sports science during the interim.

Perhaps have separate summer and winter cities.

Only drawback is the ioc doesn't get to choose a city every four years.

Re: Is a 'slow' swimming pool impeding world records?

#253

Post by dredmorbius » Thu, Aug 01, 2024, 7:00 AM UTC

Scoundreller wrote: post #103

samldev wrote: post #5

I was a college swimmer, qualified for Olympic Trials in 2012 and 2016. There are absolutely slow and fast pools. It basically comes down to two things: 1. The depth - which is only 7ft in Paris, unusually shallow for a competition pool. 2. The sides. Does the water spill over the sides into the gutters, or smash into a wall and bounce back, creating more chop. A trained eye can see all the swimmers in Paris struggli…

Dumb question I never thought about: do the circulation/filtration pumps get turned off during races? And for what minimum time before hand to let things settle? If so, I guess this would be a serious competition only thing because you wouldn’t want them off for hours.

FINA competition pool standards have recirculation minimum standards, and pumps run continuously. Further, "water distribution has to be such that no appreciable current or turbulence is created. 'Appreciable current' is defined as water movement that can move a floating basketball (filled with 6 litres of water to obtain the right buoyancy) in one direction for more than 1,25m in 60 seconds."

https://resources.fina.org/fina/document/2022/02/08/77c3058d...> (PDF)

Most competitive swimming pools have a large number of inlets with diffusers on them, laid out every 2m or so across the pool floor.

Those are circular disks about 10cm in diameter, looking vaguely like this:

  __________
  \________/
   |      |

    ^^^^^^

The carets indicate inlet water flow beneath the diffusers. The effect is that water entering the pool largely moves perpendicular to the pool floor, and slowly diffuses upwards. Water return is through the (large, wide, deep) gutters.

Because the gutters are continuously removing water from the pool, circulation needs to be on to maintain a consistent fill level.

Re: Is a 'slow' swimming pool impeding world records?

#254

Post by Rastonbury » Thu, Aug 01, 2024, 7:14 AM UTC

nl wrote: post #236

LargeWu wrote: post #187

Earlier quoted context omitted.

Additionally, anybody good enough to be prevented from setting a world record because of this pool will undoubtedly have multiple chances in other competitions with faster pools.

This isn't really the case. You need a fast pool and good competition. The Titmus vs Sanders vs Ledecky 400m could have been a world record race in another pool, but there's a pretty good chance we'll never see the three of them race each other again.

Wouldn't any of these people not try for a WR in other comps without strong competitors? WR seems more prestigious than just a win and going for it and getting it means you win that race too

Re: Is a 'slow' swimming pool impeding world records?

#255

Post by echoangle » Thu, Aug 01, 2024, 7:19 AM UTC

Scarblac wrote: post #248

echoangle wrote: post #44

Earlier quoted context omitted.

I don’t doubt that they are slower, I doubt that it’s the pool depth. To be more accurate, i have no idea if it the pool depth, but a swimmer saying that it is doesn’t tell me a lot. I’m not sure if the intuition of a swimmer can differentiate between the pool depth effect and other effects that could influence performance. I don’t doubt that something is making them slower, but i don’t believe it’s pool depth until…

Wouldn't they notice the extra turbulence affecting their legs?

Looks like they don’t if you look at the quotes in the article. Nobody said “I can feel the turbulence reflected from the bottom of the pool slowing me down”, they just said they notice they are slower and the article claims they think it might be depth-related.

Re: Is a 'slow' swimming pool impeding world records?

#256

Post by Micanthus » Thu, Aug 01, 2024, 7:24 AM UTC

skeeter2020 wrote: post #175

renewiltord wrote: post #141

Earlier quoted context omitted.

Could probably increase fairness by doubling the width and throwing away the last few lanes (leaving them empty). But would that incentivize the edges? I don't know.

It's not supposed to be fair (as in equal) though, lane assignment goes inside-to-out based on qualifying times. The easiest way to avoid the chop is to get out in front and stay there.

> The easiest way to avoid the chop is to get out in front and stay there.

While that's technically true, the drafting effect actually means that being a bit more than a body length behind the swimmer next to you is beneficial to you. That's another part of the philosophy why the fastest swimmers are assigned the center lanes, and the slowest the outermost lanes, to balance out the choppiness of being by the sides with creating a potential for drafting. Of course intentionally drafting is not a strategy that will win you the race, especially in short events, but in longer events it can be important to keep pace with the swimmer next to you while they need to expend more energy and you draft off of them either with the intention to eventually pass them or to stay ahead of the swimmers on your outside.

Re: Is a 'slow' swimming pool impeding world records?

#257

Post by rurban » Thu, Aug 01, 2024, 7:49 AM UTC

etempleton wrote: post #85

mysterydip wrote: post #11

Earlier quoted context omitted.

Would the swimmers in the center lanes have any advantage by being furthest away from the wall-induced chop?

Yes, those on the outside will have choppier waters as the water bounces off the sides of the pools. The modern competition pools do a pretty good job of reducing this effect, but it is always there.

Plus, you'd have a big advantage later if you start fast and gain a few meters from your two neighbors. Their waves would slow you down. Gliding is much faster than fighting through rough waters.

Re: Is a 'slow' swimming pool impeding world records?

#258

Post by rurban » Thu, Aug 01, 2024, 7:51 AM UTC

iknowSFR wrote: post #134

jschulenklopper wrote: post #37

Earlier quoted context omitted.

And having a better view on the competition in the neighboring lanes (just like in track running). There's even some applied psychology here, that competing swimmers 'push' each other to higher speeds because they can see each other more clearly (and 'feel' the push from someone just lagging). Putting the faster qualifiers in the middle lanes is also a better view for the spectators on both sides of the pool.

Interesting to see the 400m and 200m track and field athletes starting to favor outside lanes.

That's because of the drag in the inner curves. There the outer lanes are faster.

Re: Is a 'slow' swimming pool impeding world records?

#259

Post by dagw » Thu, Aug 01, 2024, 7:57 AM UTC

drdeca wrote: post #71

chatmasta wrote: post #69

Earlier quoted context omitted.

Yeah, but it would create weird incentives where e.g. if two people are way ahead of the pack, one of them wants to finish after the other. So do they just wait until the rest of the field catches up and then try to trick the other guy into hitting the wall first? Better to just avoid it by keeping incentives aligned with winning your qualifying heat.

Or they could randomize the order?

But then there is no incentive to try to win the qualifiers.

Re: Is a 'slow' swimming pool impeding world records?

#260

Post by rurban » Thu, Aug 01, 2024, 7:58 AM UTC

Of course it's slower. CFD simulations would also prove that.

But maybe they wanted not to be too many world records be broken, to damage control the apparent doping problem.

You can easily see on TV now, who is doped and who's not. All the dopers do have dark purple faces after the swim, usually the middle swimmers from the US, GB, AUS, Ireland, F, China, whilst the non-dopers keep their usual skin color. Italy, Hungary, Germany, ... Some hormone effect probably with these rushes.