Mist Kromo medaille 50m door stroming?

quote:

Was there a problem with the Rio pool?

I have been obsessively watching every session during the Olympics with friends (really all of us watching on our own, thousands of miles apart, but filling a WhatsApp group chat with several hundred messages a day), and during one of the sessions there was a throwaway comment by either one of the commentators or one of the swimmers about how somebody was swimming faster in one direction than another. That seemed overly suspicious to me, so I decided to check it out.

Could there be a current in the pool? (Again?)

(...)

At this point, this is just an interesting anomaly (along with the general “jaggedness” of the splitting as a whole). There could be something there that’s pushing the swimmers towards the turn end in lanes 1-4 and towards the start end in lanes 5-8.

(...)

But Barcelona and Rio were dramatically different. In both pools, there was a clear drift from lane 1 to lane 8 – which suggests that swimmers were pushed towards the start end in the upper lanes and pushed towards the turn end in the lower lanes, with the effect greater the further you get from the center. This is very concerning.

The events that such a current would have the most effect on are the 50s. After all, in a mile, you’ll get a push in one direction and a struggle in the other, but it’ll even out over the course of a race. But in a 50, the difference between a push and a pull could be the difference between a medal and not. It’s hard to know how fast a swimmer should go in a 50, but thankfully we can compare multiple performances by the same swimmer from heats to semifinals to finals.

(...)

But in Barcelona and Rio? That’s a tremendous effect. 48% of the improvement in time in Rio, and 36% in Barcelona, can be explained by moving from the left hand side of the pool to the right hand side, with an extremely small pvalue. The slope is large as well, 0.2% improvement per lane as swimmers move to the higher lane numbers. That doesn’t seem like a lot, but consider that 2nd through 4th place in the womens 50 free came from the favored lanes and just 0.1 seconds separated Simone Manuel in 2nd (from lane 7) from Ranomi Kromowidjojo in 6th (from lane 3). That’s 0.4% of the race, and it looks as if Manuel got a relative 0.8% boost.

These results are very disconcerting to me, but do not in and of themselves prove that there is a problem. However, the data strongly point to serious problem in the pool which could have led to an unfair competitive environment, especially in the 50m freestyles. I think it should be investigated.

https://swimswam.com/problem-rio-pool/