[johnp314]

It would be interesting to see a comparison of lane effect, say for instance, re-running a race after let's say a weeks rest with the top finishers now nearest the side walls and the lowest finishers in the center lanes. Oh and for incentive, let's say the average of their two times determines the winners.

[sandworm101]

The human factor would make this very difficult. A more scientific test might be to use RC boats with tightly regulated power outputs, with a wave machine to ensure consistency.

[dredmorbius]

The fact that swimming competitions are so very close, often down to 100ths of a second, doesn't much help.

Olympic and similar competitions are timed to the nearest 1,000th of a second, but any result within the same 100th is considered a tie as that last bit is just entirely arbitrary, in part because pool dimensions themselves are not accurate to this degree. (The FINA standards mentioned in my earlier comment addresses dimensions accuracy standards.) The Olympics did break ties at the 1/1,000s standard in 1972, but has since judged any result within 1/100th as a tie:

<https://olympstats.com/2014/02/12/timing-accuracy-at-the-oly...>

[dr_dshiv]

Random assignment should make it easy to detect, depending on the size of the effect