So it reads, Harry Potter is at Ollivander's Wand Shop. As we all know, the wand must choose the wizard. So Harry cannot make the choice himself. He interprets the wand selection as a random process so he can compare the probabilities of different outcomes. The wood types available are holly, elm, maple, and wenge, wenge, wenge? The core materials on offer are phoenix feather, unicorn hair, dragon scale, raven feather, and thestral tail. All right.