Hi!
Good question! Research has shown that thinking about motor patterns actually causes those neurons to fire, strengthening there connections. Our imagination is able to practice instigating these motor patterns in a variety of contexts (some outside the realms of physics!). This type of meditation is very beneficial to strengthening your motor coordination. Other than that though, meditation is also extremely beneficial for practicing a state of calm. Our prefrontal cortex is the logic/ decision maker of our brain. When we get stressed, neuronal and hormonal mechanisms actually act to inhibit our prefrontal cortex. This means, when we get stressed or anxious our ability to logic and reason is bioloigcally reduced. This can have real consequences before and during a game. Having ways you can practice bringing yourself back to a calm state, disengaging thate emotional brake on your logic, will help you be a better player on the court.
So, in short, "mental strength" will help you be a better player by increasing your ability to stay logical and engage the appropriate muscle memory, reflexively. Lose your calm, lose your logic, lose your reflexes. That's just my two cents anyways, hope this helped!
