Kasparov is the only player who has surpassed Carlsen in the FIDE rating list, reaching 2851 in July 1999. He is also widely regarded as one of the greatest players of all time and a chess legend. He retired from competitive chess in 2005 and became a political activist and a writer.
Caruana is the second-highest rated player in history, reaching 2844 in October 2014. He is the current world No. 2 and the challenger to Carlsen in the 2018 World Chess Championship, where he narrowly lost in the tiebreaks. He is also the first American to compete for the world title since Bobby Fischer in 1972.
Aronian is one of the most consistent and creative players in the world, reaching a peak rating of 2830 in March 2014. He is the current world No. 5 and the leader of the Armenian national team, which has won three Olympiad gold medals. He is also known for his friendly rivalry and friendship with Carlsen.
Ding is the highest-rated Chinese player in history, reaching a peak rating of 2816 in September 2019. He is the current world No. 3 and the winner of the 2019 Grand Chess Tour. He is also the only player to have qualified for the Candidates Tournament twice without losing a single game.
Topalov is a former world No. 1 and the FIDE World Chess Champion from 2005 to 2006. He reached a peak rating of 2816 in July 2015 and challenged Carlsen for the world title in 2010, where he lost by a single point. He is also known for his aggressive and dynamic style of play.