London 1883 chess tournament

Remarkably, Zukertort was already assured of victory with three rounds to go, having scored an astonishing 22/23.

A common story relates to an incident that occurred at the tournament banquet, when the St. George Chess Club President proposed a toast to the best chess player in the world and both Steinitz and Zukertort stood up at the same time to thank him.

[2] A game between Mason and Winawer was played, adjourned and resumed, but upon resumption the black knight on e7 was mistakenly placed on d7.

Neither player noticed at the time and Winawer played the illegal, but powerful, Nc5!

setting up a Ne4+ and eventually winning the match, with the mistake not being spotted until after the game concluded.