Something I learned from the article that I didn't realize before is that the surface of the ice used isn't smooth; they pebble it on purpose in order to give it the texture required for the stone to curl. Apparently, getting the right texture is difficult enough that it takes an experienced professional to get it right, and they haven't had satisfactory results trying to automate it. Wild peek into something that I didn't even know was a thing!
I'm sure along with discovering this, it also gave you an explanation for the science of sweeping which is also super neat and to the casual observer, not a well understood part of the game. At the micro level, the abrasive texture of the brooms is melting pebble (not entirely, just temporarily along the sweeping path) and affecting distance, deceleration, curl.
Sorry, kinda nerding out over seeing a curling article on HN.
This is completely true! It also varies a _lot_ between clubs, with curlers describing different rinks as being "straight" or "curly", with the latter being more densely pebbled and thus prone rocks curling more. Some of the better players I curled with had notebooks full of points they'd remembered from each rink they'd played. As one would imagine, the home team advantage is enormous in amateur curling.
Each rink has a professional ice maker on staff whose job it is to maintain the rink for everyone to play on. Rinks usually need pebbling between games, so the ice maker or their apprentice is pretty much on staff the entire time people are using the facility. It seems to be a labor of love, spending hours and hours a day hunched over sprinkling water on a sheet of ice, only to have it all swept away in a matter of hours. You end up being known by name by the entirety of the club, and a lot of folks buy you a nice gift come Christmas!
What's interesting is that several things can affect the sheet of ice and make sheets even within the same building behave differently. Often if sheets on the end of the building have an outside wall, you'll see the outside sheets behave different from the middle sheets of ice. The same thing can happen depending on how cold it is outside. It's grown more scientific in recent years, especially at the professional level.
Ice makers are indeed held to a challenging task and what you said is true - they're recognized across the club, on site, by basically every member and they more often get blame than praise for how the ice affects a game!
During one of the gold medal matches they were talking about how play is different because with only one game going on there were fewer people (aka heaters) in the building
Cricket is somewhat like this. Preparing a 'good' pitch (not too green or uneven, which favours bowlers, but also not too flat and lifeless) is hard. And in the longer forms of the game the pitch seriously deteriorates over the days the game is played. So a good groundskeeper also has to try to arrange a pitch that degrades gracefully.
Coupled to that, the surface is very climate and soil dependent, so there are significant differences between grounds (especially between different continents!) even if they all had the same ground staff.
From what I can understand the challenge with cricket pitches is that you don’t want grass on the surface, but you need strong grass roots, to prevent degradation as balls are hurled into a small part of the pitch at high speed hundreds of times.
Wimbledon similarly has groundsmen who can almost kill grass without killing it. There, the ideal into have very short grass (8mm, according to https://www.thesun.co.uk/sport/6667985/wimbledon-head-ground...) and a strong root system. Still, two weeks of tennis each year changes the courts from fully green to, at places, small dust bowls.
Seems like there's plenty of allowance for variation in the air pressure of footballs (American NFL). So much so that we ended up with Deflategate in 2014:
Alpine Skiing. The person who picks where to put the poles to ski around, and at higher levels of competition the person in charge of how the snow is prepared.
