BREAUX BRIDGE, La. — The free throw line is the edge of the concrete slab, where the driveway meets a trampled, brown patch of grass, once lush green like the rest of the yard but since smothered by tennis shoes, bare feet and whatever else they wear in south Louisiana for front-yard basketball. The three-point arc is naturally marked by a chain-link fence that separates the yard from a two-lane street. That’s one of Corey Davis Jr.’s favorite spots, and his grandfather, Alfred Dalcourt, stands behind the fence to illustrate this, his back to the road as he mimes a 22-foot jumper.