An open is a tournament which is attended by a large number, thirty up to a thousand, chess players of varying levels - from amateurs to grandmasters.
The names of legendary champions are known even to people remotely familiar with the ancient game - Kasparov, Karpov, Fischer, Capablanca, Carlsen ...
Books are written about them, films and TV shows made..
The number of elite players is small – the 20-30 top players on the rating list of the International Chess Federation (FIDE). According to various estimates, chess is played by between 100 and 600 million people.
Professionals and semi-professionals make up from two to ten thousand of them.
Opens are their bread and butter, as up to 95 percent of all chess competitions are open tournaments.