It seems to me that running a corpus of produced text (be it your own or literary) misses a lot of potential optimisation. It completely misses things like control key usage, arrow keys, number pad, etc. (And ESC! Vim user here.)
Also the timing of keystrokes. Focusing on programming for a moment, I would assume most people type is short bursts of maybe one or two hundred keystrokes, not sustained typing of paragraphs and paragraphs.
And what about characters that do not have a key on your keyboard (such as my use of “§” below)?
I suspect that to “do it right™” you would need a keystroke logger, and possibly log your clipboard usage as well, for a thorough analysis.
(Vi usage adds a complication to this, I think. You could almost think of command mode as a different keyboard layout. I can't image wanting to HJKL navigation key positions to move. Any analysis would have to make that distinction.)
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Switching gears for a moment, I recently tried out a prototype keyboard design, and while discussing it with the developer discovered some interesting differences in our typing habits. For instance, I exclusively use my left thumb for the space bar, whereas he used his right. I also tend to use the left ctrl, alt, shift keys and never the right.
It also seems that when drumming my fingers on a desk, I find rolling outwards - index to pinky - much easier and natural than rolling inwards, which seems to be more common. (I am right handed and left footed, BTW.)
