That bit made no sense. It might have made some sense if it was measured from the moment you get physical feedback from the keyboard that the key has been pres

That bit made no sense. It might have made some sense if it was measured from the moment you get physical feedback from the keyboard that the key has been pressed. But I suspect that this isn't as straight forward as it is tempting to believe. (For instance if the mechanical feedback and the moment of contact do not occur at the exact same moment)