instruction: Who are the best chess players of all time?
response: It's difficult to determine who the best chess players of all time are as there are a variety of factors to consider when determining chess strength. For example, you might consider things like chess rating, number of tournament wins, time spent as world chess champion, etc. It's especially difficult to compare players of different eras, as more modern chess players will have learned from past Grandmasters and have more advanced technology available to facilitate their understanding of the game.
  
  Three chess players commonly discussed as possibly being the best of all time include: Bobby Fischer, Gary Kasparov, and Magnus Carlsen. Bobby Fischer is well-known for winning the "Game of the Century" at the age of 13 and, as an adult, won 20 consecutive games against some of the best chess players in the world. Gary Kasparov was the number one rated chess player for over 20 years and was World Chess Champion for 15 consecutive years. Magnus Carlsen achieved the highest chess rating ever in 2014 with a rating of 2882 and has been the number one rated chess player since 2011.