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On Feb. 21, Kiril Georgiev of Bulgaria played 360 people simultaneously in Sofia, Bulgaria, breaking the world record for such a feat. His final score was 284 wins, 70 draws and 6 losses. The previous record holder, Andrew Martin, an English international master, had played 321 opponents at Wellington College in Berkshire, England, on Feb. 21, 2004. Susan Polgar of the United States played 326 people simultaneously at a mall in Palm Beach Gardens, Fla., in August 2005, but the Guinness Book of World Records did not recognize her record as official.

It took Georgiev more than 14 hours to set his record. Oddly enough, that effort did not take as long as the longest game in recent memory — a 269-move, 20 hour, 15 minute, marathon between Ivan Nikolic and Goran Arsovic, two Serbians, that began on Feb. 17, 1989. The game ended in a draw. Another long game, at the 1969 World Junior Championship, between Kenneth Rogoff of the United States, who is now a prominent economist, and Arthur Williams of Britain, not only lasted 221 moves, but was notable because the first capture did not occur until the 94th move. That game, too, ended in a draw.

While Georgiev’s exhibition was the largest individual effort, it does not compare with the largest number of games played simultaneously. According to Guinness, that happened on Oct. 21, 2006, in Mexico City, when hundreds of masters played against 20 to 25 opponents each, for a total of 13,446 games at the same time.

Of all the records in chess, the most remarkable may be games played simultaneously blindfold. George Koltanowski, who was born in Belgium but lived most of his life in the United States, set the official record in 1934 by playing 34 games blindfold, winning 24 and drawing 10. On Dec. 4, 1960, Koltanowski reportedly played 56 games blindfold, winning 50 and drawing 6.

Koltanowski had a prodigious memory which he used to perform something called the knight’s tour. In this exhibition, he would have members of an audience enter information on each of the 64 squares of a chess board drawn on a chalk board. Then, he would turn his back to it and, beginning on a square chosen at random, he would jump from square to square imitating the movements of a knight. On each square, he would recite the information put there by the audience members until he had covered the entire board without landing on any square twice.

Given the nature of chess, there are many other records, some of which are compiled on Wikipedia. Three years ago, Chessbase.com also listed some chess records, courtesy of Edward Winter, a British historian. One amusing one was a game by mail that took 16 years to complete.