There is evidence of decreasing memory with age, many brain function related diseases like Alzheimer higher risk for older people. Senility and memory loss are

There is evidence of decreasing memory with age, many brain function related diseases like Alzheimer higher risk for older people. Senility and memory loss are commonly related. Also certain types of information is more easier learnt when you are younger like multiple languages. I believe there is research on learning pedagogies for senior citizens having different approaches than children factoring in the ability to learn quickly. Most mathematicans and many other scientists achieve the peek before 40, while there are exceptions like Euler or gauss it is not common. Even in tech you find a lot more younger workers than other more stable technical fields as the learning curve is recurring and steeper than in other fields I wouldn't disagree there is more physical stamina required for tournaments, however I doubt it so difficult for players in their 40s/50s cannot manage it without loosing competitive advantage.