Thanks guys for the input ...But specially those from the US I think you are too focused on this numbers/statistics idea because of the sparsity of players in your areas. I get that. But many of the criteria you mentionned are satisfied in other asian countries (Japan, Korea) and also in Europe. While the number game helps I don't think it is the main factor. UPSIDEDOWNCARL point supports my argument that this is not a numbers thing. NextLevel agrees on the short receive advantage but I believe it is the biggest contributor to the huge difference between CNT and the rest of the world, everything else is already there to a certain degree but still doesn't explain that phenomenal gab of difference (talent, numbers, discpline etc...).
I have some personal excperience on this. First a bit of history. Sweden's importance in table tennis didn't begin with Waldner and Persson. It actually dates to the early-mid 60s (or earlier if you include Tage Flissberg). Recall Alser, Johansson, then Bengtsson, also Appelgren then Waldner and Persson, and then it died out. So by the time Waldner and Persson came about, there was a long history of greatness (but only for male players). Sadly, nobody in Sweden now is a threat to win a world championship (and never were for women).
As a kid my family lived in Sweden in the early 70s and that is where I learned to play. There was a school next to our apartment, and there was a coach, and we had a league we could play in against other teams from all over Stockholm. You could see the top players on TV. You could see them in advertisements. The only other sports where Sweden was good was ice hockey and nordic skiing (this was before Bjorn Borg). China in those years was in turmoil, so a lot of the top players in that era were from Japan and eastern Europe, where TT was heavily subsidized by governments, as some of my close friends who played on former Yugoslavian junior national teams before emigrating to the US have described to me. That meant that many of the elements I just described were present, especially in Hungary and Yugoslavia, albeit on a smaller scale than we see in China today, but it didn't matter as much since China was till in the midst and immediate aftermath of their Cultural Revolution. Those elements no longer exist in those places. (Yugloslavia is not even a thing anymore) and those countries no longer produce top players who could conceivably win a world championship; the last one (if one is charitable) maybe Primorac. Put another way, those countries don't care about TT anymore.
The other thing I would note is that every country occasionally produces a great player. One of my all time favorites (Gatien) is French for example. I studied him a lot and tried as best as I could to copy some of it. Schlager comes to mind. Timo Boll was a threat at least. These days Japan produces the most if you include both men and women. Harimoto will probably do it.
But to say that any country besides Sweden in the 90s has actually
challenged Chinese dominance, especially among male players is simply incorrect -- with the possible exception of Japanese women at the present time (and note if you will that everyone in Japan who knows anything about sports knows who they are). The NUMBER of great players China produces, and the number they have in the pipeline is just beyond amazing. In Germany, where there is a lot of what you need you can produce quite a few players in the world top 30. But have they ever challenged Chinese dominance?
And of course, everyone may be looking to one single "superpower" that all Chinese players have, but that is impossible because all of their great players are quite different from each other. There is no way to say for example that Xu Xin and FZD play anything alike. And any suggestion that it is Hurricane that makes the difference just makes me laugh.
What they all have in common though is the level of competition they have had to overcome at every stage of their playing careers, starting in childhood, and the opportunites they have to devote 100% of the days and nights to the sport. So yes, that means they all have great return of serve, and great footwork, etc. etc. but they accomplish it in somewhat different ways.
So yes, it is very much a numbers game. Another way to say it is that China simply CARES about TT more than anyone else. Last time I was in Sweden some guys about my age and a bit younger told me that the kinds of infrastucture they had as kids is hard to find now. They don't care anymore. That doesn't mean that great players won't pop up from other places, of course they will. But that doesn't mean any other country is likely to challenge Chinese dominance for any length of time. Sweden certainly isn't doing it.
Maybe Japan, for a little while.