I think, by numbers, the most sport where one country has been most dominant is table tennis, by a fairly wide margin. China has owned that sport.
Of 28 men’s singles medals on offer since the sport entered the Olympics in 1988, China owns 16 of them, including 6 of 9 golds. Of the same 28 medals on offer for women’s singles, it’s even more lopsided, with China owning 19, and all 9 gold medals. They’ve won every men’s doubles and all but one women’s doubles. They’ve won every single team gold for both men and women.
They have 60 total Olympic table tennis medals. That’s more than the next 11 countries combined, and the next closest country (S.Korea) has 18.
Damn!
My wife (Chinese) is the least athletic human I’ve ever encountered, except when we play table tennis. It’s definitely a thing.
Unrelated but my uncle in law is shockingly good at table tennis. He’s 80, only has one lung, but has incredible hand eye coordination, reflexes, and is just a stud (former 3 hour marathoner, fantastic golfer, climbed Kilimanjaro at 70 with the one lung).
Whenever my brother in law and I go to visit, he routinely smokes us both with ease. I don’t think either of us have won a game against him and we are both 40 and pretty good athletes. I’m considering taking lessons in secret so I can finally get him on our Xmas visit this year.
I’ll probably get the details wrong but I saw where there’s an older Chinese woman, I think in her late 50’s, that was a pretty good table tennis player in her youth. Presumably at some point emigrated to Peru (?), said she didn’t play for decades before taking it back up during Covid and is now representing her new country at the Olympics.