- either as 11 empty holes between the holds; - as 11 holes, start counting 1 just above hold A; - or as 11 holes, start counting with hold A as number 1.

Another real-life example, is a plumber who tells the construction worker that the distance between the holes for hot and cold water needs to be 15 cm. This was meant to be measured center to center, but the constructor worker interpreted it as the distance from the right side of the first hole to the left side of the second. The result can still be admired in our house, 10 years later.

> A few of the climbers had said that the automatic belay ropes on the right hand lane did not feel right, so the cherry picker was replacing those and not the hold that I had noticed being out of place. The climbers had noticed something wasn’t quite right, but hadn’t said anything about the out of place hold.

It was probably just two separate problems.

Literally it was an off-by-one error. Literally, literal meaning.

They might not use the hold by physically touching it, but they might still use it as a visual indicator of where the other holds are in relation. These competitors are used to the same layout for many years. If there is a slight misrepresentation it can surely put them off.

But I think it's possible that 'extra' holds are potentially like 'junk' DNA. People fall into the trap of thinking that DNA is useless if it's never transcribed, but we know that's not actually the case. Non-expressed DNA can do things like alter binding affinity for neighboring sequences, affecting how often those neighboring sequences are expressed. I think it's possible that climbers are taking in a lot of information subconsciously as they sprint through this route in order to mike very small adjustments. The position of surrounding holds, even ones they never touch, could very well be a part of that information stream. They're fighting over hundredths of a second, so even a very small effect could be meaningful.

Also the author rules out psychology, but I wouldn't, especially since there were multiple confirmed errors in the route preparation, which I expect could reduce one's trust in the fairness of the competition. In the moment, I might start to wonder, "If one hold was out of place, why not more? Is anyone even checking this?" even if untrue / unlikely.

Am I the only one?

This is odd to me since I've successfully used stereoscopy in the past to find small differences. For some reason, with this image, rather than causing a change in perceived z-level, my eyes fight for dominance and my left ends up winning.

So the day of your fifth birthday is the first day of your sixth year alive.

Plenty of other sport are pretty much the same each time, particularly track and field.

There are other forms of competition:

- bouldering: how many of 4 short boulder problems can you finish

- lead: how high can you get on a longer, higher route (pictured on the right of the image in the article)

In these ones the problems are switched up every competition.

Not to mention other variables outside of the human body. Perhaps the type of rope could matter in your performance. The age of the holds could matter too; even when the governing body standardizes on a replacement period for holds, I'm sure competitors would have strong opinions about the difference between a hold at the start of its service life versus one about to be replaced.

Also, the one thing I love seeing in physical contests is how competitors eke out the last bit of performance advantage with sheer willpower. Muscle memory takes care of the actions but performance and willpower is a conscious effort.

In short, no, I don't think competitors can literally turn off their conscious brain and just let muscle memory take over. If a field has jargon, there's a hell lot to geek over it.

Are you?