n the early days of first-person shooters, Fong says the keymappings were all over the place, and even the great Thresh had only just started to play with a mouse at all. Imagine him just a few years before, sometime around 1993, as a teenager losing a match of Doom against his brother Lyle. Like many Doom players, Fong used only the keyboard. Without the need to look up or down, it was a natural choice—so much that using a mouse was even considered weird. His brother, however, was playing with a keyboard and trackball, and he was winning. It wasn’t every game—both were excellent players—but Lyle won enough that one summer Fong decided he had to learn to play with a mouse. After that, he was unbeatable.