A is a kernel extension (kext) or system software that translates the raw USB data from your gamepad into something macOS’s Game Controller Framework can understand.
That’s when she remembered a yellowed sticky note on her monitor: “USB Prober + I/O Kit Family.”
Obscure or generic USB gamepads (DragonRise, SNES USB replicas). This is a universal HID driver that lets you map any USB button press to a keyboard key or mouse click. It is not a game controller driver in the DirectInput sense, but it makes every USB device work.