Why is Waverly good at chess in "Rules of the Game"?

At the beginning of the story, Waverly notes that she learned the art of "invisible strength" from her mother when she was six years old. If Waverly doesn't complain or ask for the salted plums, her mother will buy them. Her silence gives her an advantage.
Her mother compares this strength to the wind. As Waverly is learning chess strategies, she adds, "I discovered that for the whole game one must gather invisible strengths and see the endgame before the game begins." Knowing these strategies beforehand is a distinct advantage. To increase that advantage, it is best to remain "silent." In other words, Waverly must be patient and not let her opponent see her being anxious, worried, or uneasy. She must have a good temperament and a better poker face. The less her opponent knows, the better off she will be:

I also found out why I should never reveal "why" to others. A little knowledge withheld is a great advantage one should store for future use. That is the power of chess. It is a game of secrets in which one must show and never tell.

She loved devising and remembering these "secret" strategies. She would stare at the chess board and play out the moves in her mind. She continued to learn from an old man, Lau Po, by playing chess with him near the playground. Eventually, she became better than him. Waverly liked the idea that her invisible strength was like the wind: unseen by her opponents until it was too late. She begins to understand how invisible strength can be used in other aspects of her life. In the last line of the story, she even proposes to use this strength in dealing with her mother.
Waverly thrives on her success and wants to become even better because she is proud of her individual achievements. When her mother brags about her success, Waverly is embarrassed and feels like that success is somehow being taken away from her.