Why There Are So Many Ties in Swimming

0.5 seconds in the 1500 is almost nothing though. In shorter races the difference is less meaningful

Tolerance works two ways, so the difference could be 1.8m.

However, I would expect that there is a high correlation between the size lengths of lanes in a single pool, so that one doesn't have one lane 3 centimeters too long and the one next to be 3 centimeters too short. It's weird that the standard doesn't make any requirements on that.

Also, touch plates get installed after the pool is constructed. I would expect those could easily be made to compensate for any size differences. That would leave a size difference at the start, but that's easily fixed, too.

Having said that, every few years or so there's a newspaper article of a swimming pool that gets constructed to be 50m, where the constructors forget about those touch plates.

This would only matter for national and world records - swimmers competing in finals are swimming against each other at the same time, under identical pool conditions (ignoring any psychological differences between lanes - e.g. breathing towards your cheering fans and family on odd laps vs. even ones, etc).

My reading of that was that every lane must be within 3 cm of every other lane.

You got me thinking about what other factors could affect the result at various degrees of precision. By my math [1], the time it takes for the sound of the starting buzzer to reach the ears of swimmers at opposite ends of the pool could actually affect the outcome measured in hundredths of a second. But it's an order of magnitude smaller effect than the lane lengths varying by 3cm. Of course, they could remedy this (and for all I know, maybe they do!) by having one starting buzzer speaker placed at the same distance behind each swimmer.

[1] Each lane is 2.13m wide, so the swimmers in lanes #1 and #8 are 14.91m apart. If the buzzer were placed right next to swimmer 1, it would take ~0.044s longer to reach swimmer 8's ear (using 340.29 m/s as the speed of sound). Or if it were right in the middle between swimmers 4 & 5, it would reach swimmers 4 & 5 ~0.019s before it reached 1 & 8.

Differences in wall-to-wall distances at middle and longer distances are less important than in shorter distances. The article uses a 100m race. But consider a 50m race. 3 cm over 5,000 cm is a .06% difference. That's easily 1/100 of a second in a 24 second race.

But in longer races, there are many other factors that add noise to this. For one, swimmers aren't competing in a pool where one has to swim 1,500m and another 1,499m pool. They are making turns. A 3cm different is well within the 'noise' of a flip turn.

Also, there is drafting and bow waves, and other things going on that have a bigger effect than the 3cm per length.

Remember that concrete expands and contracts, and the pressure of the water influences that process.

As they mention the alternative is to not have swimming.

Well yes, but Olympic athletes and audiences tend not to like it very much if we try to do 50 replicates of the same race.

I doubt this means we are hitting the human + tech ceiling. Many runners ran 4:02 miles before Roger Bannister broke the 4 minute mile. That was a mental ceiling.

I suspect a similar mental issue exists in swimming. The goal you're trying to beat is your own world record or whatever you think is achievable at your current fitness. Other swimmers are aiming for the same goal. Then when swimming, you see the swimmer next to you, and he's swimming as fast as he can, you're pushing each other, the end result just may be that you push each other to the point where you get the same time, and sometimes that will be an Olympic or World Record, and sometimes it won't.

It's not clear whether lane placement affects results, but it's true that the middle lanes are often favored, and qualification systems tend to place better-performing swimmers towards the middle. Here's two non-professional discussions on the matter:

[1] https://www.quora.com/In-competitive-swimming-why-are-the-in...

[2] http://sports.stackexchange.com/questions/1326/in-swimming-i...

The wave-eating lanelines do an excellent job of removing most of the effects of wakes. Turbulance from actual strokes is pretty minimised. Worst case is probably in the butterfly where the wake is maximised.

Many other pool features, including both vents (bottom-mounted and highly deflected/diffused) and gutters (in the 1970s - 1980s usually large, below-deck, now often a set of ground-flush slats into which waves are absorbed) also minimise pool turbulence.

granted anecdotal, but when I was a swimmer lore was that center lanes were the fastest due to currents. They do a lot to counter these things though, special lane ropes, deeper pools etc. If you ever watch a lesser event (like non-olympic) they put less effort into dealing with the turbulence. see: https://youtu.be/Igf8PagbGKU?t=1m9s as an example. look 3-5m behind those guys and see how crazy the water is and its spilling all over the other lanes. Also when they flip turn we used to wonder if it was better to go under your forward current that you were pushing just a second prior.

But we could fairly easily measure it; we just don't find it worth the trouble.

Also, as to the ties, that's almost purely a political choice made by the sporting body. In rowing, for example, the winner in the Olympic final was decided by looking at the finish photo (http://www.telegraph.co.uk/news/2016/08/13/theres-only-one-g...), with both rowers getting the same time in hundreds of a second.

I doubt they can align six boats to that precision at the start, even with equipment for holding the bows of the boats at the starting line.

Eh, anything less than 0.0125s is 3cm and a tie. Pretty darn close to 0.01s and all you need to do is make sure the pool is accurate to within 2.3cm instead...

Much more interesting to think about the delta between the clock that's accurate to hundredths.

Someone could win with a time of 23.01s vs second places 23.00s... But is the delta really 0.01s, or was second place 23.00999999 with a delta of 0.00000001s?

If you measure the time the swimmers take very precisely and thus can tell that one swimmer reached the target a few milliseconds earlier, that could be because they are a faster swimmer than the second-placed. Or they could just have had a shorter lane to swim and win despite being slightly slower than the other. They swim around 2.39 mm per ms, and lane differences are allowed to be up to 3 cm, so this can make ~12 ms difference where you don't know where it is from.