Chess is an idle person’s game – it is for people who hate any form of physical efforts.
To go up the rating scales, you need to win many tournaments and you cannot do so unless you are physically fit and mentally alert. Mikhail Tal in his heyday was regarded as a magician of chess, so brilliant were his combinatory skills in the middle game. But his reign at the top (as world champion) was short-lived and even though he continued to win other tournaments in his relatively short life of 56 years, the results were not consistent. All this because he had a kidney problem and could not take the strain of the long series of games required in tournaments. The amount of physical strain undergone by top level chess players was amply illustrated when Karpov lost weight by about 10kg (can you believe it?) at the end of his matches with Kasparov in 1984-85.
Chess is an old man’s game – retired people who have nothing else to do play chess to pass their time.
There have been about 15 players who became grandmasters before they were 15 years old, the youngest (Sergey Karjakin) achieving it at a ripe old age of 12 years 7 months! Kasparov became World Champion at the age of 22.
With so many bright young players around, you cannot expect to hold ground when you are past 50.
Provided one remains physically and mentally active, you can give a lesson or two to many players half your age. Victor Korchnoi was a World Championship candidate at the age of 60 (though he did not win it) and even at the age of 78, remains an active grandmaster in tournament circuits. Mikhail Botvinnik won several World Championships, the last one at the age of 50 against a player of the caliber of Mikhail Tal who was just half his age!
The next World Champion will be a computer.
Till the second Deep Blue computer from IBM in 1997 won a 6 match game (2 wins, 1 loss, 3 draws) against the then World Champion Gary Kasparov, no computer had prevailed against a grandmaster. With its reported ability to analyse 200 million positions per second, the win could be considered as a result of brute force! Besides, I feel that to gain an immense publicity, IBM did not play fair in their eagerness to win. In all chess tournaments, records of the moves by players are kept (you can see what Paul Morphy played in the 1850s!) and it is a common practice for all top players to analyze the games of their opponents to decide on their own game plan. IBM had access to all games played by Kasparov but when Kasparov wanted to see the records of earlier games by Deep Blue, IBM refused to comply and they also declined When Kasparov wanted to have a rematch later. All in all, it is still man over machine.