I feel it is too late to become an excellent chess player at the age of 50. It's because you've begun having bodily issues. The ideal age is usually between 28 and 32 years old. GMs begin playing at an early age, although I believe it is preferable to begin at the age of 16. The main problem with people who play chess at a very advanced age is that their brains are not functioning at their best. Their memories aren't so good anymore, and that makes it difficult for them to cope with all the rules and concepts of the game. Also, their eyes start going bad soon after they stop seeing things on the board every day. That's why I think it's better to start practicing chess when you're young and your brain is still capable of learning new things. There have been many great players in history who had to deal with the fact that they were too old to join some kind of tournament. US president John F. Kennedy was only forty-three when he was killed. But even he couldn't escape the consequences of having his brain damaged by being shot in the head. A lot of GMs say that being a grandmaster is more than just being good at chess; it's also about having intelligence and creativity, which means that someone who is really talented but has a bad memory or isn't so smart anyway won't make it to such a high level.