Everyone’s mental stamina level is different, so pace yourself. Start out playing what is fairly easy amount for you to do without mental fatigue for a week or two. Then slowly add an additional game to work up mental stamina. You might notice if certain times of day work better for you, or if there is any link to your ability to do better in certain other conditions (eating specific foods, drinking water, stress level, etc.).
And be sure in addition to playing the games, you are following the nutrition, hydration, supplement, exercise, and sleep protocols outlined here as they will directly impact your brain’s fitness. Best to you! -Coach Zoe