Grandmaster
A grandmaster is a world-class expert in chess or martial arts.
In chess, it is estimated that it takes about 12,500 hours of study and practice in order to attain the title of grandmaster. That is based on an estimate of 20 hours per week for 11 years. Alternatively, it is estimated that one has to play 7,000 games or so to become a grandmaster, not including study and viewing games by others.
A chess grandmaster has attained a FIDE rating of 2500 and satisfied additional requirements, such as doing well in tournaments.[1]
Top, highly competitive grandmasters train from 4 to 7 hours a day on an expensive computer capable of running sophisticated chess programs, and the top players compete in a dozen or so tournaments each year.[2]
Prize money is scarce: the top prize in the 2018 Candidates tournament was only €95,000, which selected who would play the reigning world champion, and it was the largest purse the winner had ever earned. In the world championship itself in 2018, the winner took €600,000 while the loser took €400,000.
