My dad plays chess like a mathematician. Each of his turns stretch on while he contemplates the board from every angle and I forget my grand strategy. To entertain myself in these gaps, I look where his gaze falls. When he mutters to himself, is he frustrated with my playing? Or is that another tactic meant to confuse me further? When he finally chooses one lucky piece with a heavy sigh, how that piece gleams in the TV light as he lifts it—slowly, as he does most things. My dad is okay at defense. But he’s ruthless at offense, felling…