The availibility of inexpensive computer players and easy access to software for the downloading and reviewing of games - only seconds or minutes after they have been played - have levelled the chess playing field.
Web-availiable analysis by elite players and the growing muliplicity of strong international tournaments are also factors.
Geography and national origin are no longer the trumps they once were. Individual predilection and motivation have taken center stage.
How else is one to account for the success of such players as Magnus Carlsen of Norway and Wesley So of the Philippines or even Hikaru Nakumara of the US, each of whom has had to look for the most part outside his national boundaries for top-notch competition and inspiration?
A look at the recent FIDE rating list of the top players confirms the trend.
Individual players from 16 different countries are currently listed among the top 20 players in the world, including four from Russia (one, Sergei Karjakin originally a native Ukrainian grandmaster) and two from the US (including Wesley So, a Filipino only recently registered as a US player).
From the perspective of the pre-computer era when 30 or 40 per cent of those among the top group were from the Soviet Union, the change in the chess landscape is remarkable.
Shelby Lyman, Basic Chess Features