Ok, the reach-ability pictures. If I would know it is so much booring work I would not agree to post them. Me, stupid
Here is the layout so that we know the positions of keys I'm talking about.
The pictures are done using a hand which has 195 mm from the tip of the middle finger to the first wrinkle on the wrist. So it is probably bigger than average. The home position is at Space-J-K-L-; keys. Despite that most pictures have thumb positioned on the Alt key. It is done that way so that the wrist position is always about the same. I keep my wrist at the rests in such a position so that I can just reach the nearest bottom corner of the Alt key. Well I should keep the wrist just over the rests but I'm lazy.
As for as the comfort to reach a key, the rows are ordered like this (from the most easy to the most hard): home row, row just below it, row just above home row, the bottom row, the top row.
So here are the pictures of the top row reach-ability:
The outer pinkie column. The top two keys are not a problem. No wrist movement needed. The bottom two keys (enter, keypad shift) require a slight wrist rotation.
The inner pointing finger column. Pause key is easy to reach without wrist movement. The two bottom keys (application, insert) require a slight wrist rotation.
The outer thumb cluster keys. All easy to reach without any wrist movement. Of course the alt key is pressed only in the corner but that is not bothering me.
The inner thumb cluster keys. Space key is the home key for thumb so it is the most easy
![Smile :)](./images/smilies/icon_e_smile.gif)
. Shift key is the second most easy to reach thumb key. Keypad Shift key is easy (still not writ movement). Win key is the worst from the 4 inner thumb keys. I do also a slight wrist rotation there.
I typically do not do chords on one thumb cluster if the chord needs only two modifiers. In such a case, I press one of the modifiers on one thumb cluster and the second modifier on the second thumb cluster. But there are exceptions of course:
More complicated chords on the thumb cluster which use only one thumb (no other fingers involved). From these I use only Win-Shift and Ctrl-Alt. Both of them are easy to do. It would be easier to do LayerShift-Space chord than Win-Shift but LayerShift-Space chord is not useful to me. The keys in these chords have different height. The idea is to press the higher key from a side and with the very tip of the thumb. This compensates for the keycap height difference. I do a tiny wrist rotation for Win-Shift chord.
Shift-Space and KeypadShift-Win chords would be much
easier with 3dPrinted keycpas which close the space between them but I do not need these chords so I did not bother with custom keycaps. Both of them require significant wrist rotation and the second one also a small movement.
Edit: With the special keycpas, there would not be any wrist movement for Shift-Space chord and there may be a slight wrist rotation or movement for the KeypadShift-Win chord.
Chords on the thumb cluster I never do but that can be reasonably done. PgUp-PgDown chord is actually very easy to do without any wrist movement but it is not useful. Shift-PgUp and Win-PgDown require wrist rotation, the second one quite significant and maybe even a movement.
Extreme chords - i.e. the ones which require more than 2 modifiers. I do all the modifiers with one hand by moving hand to the thumb keys. I use thumb for one key and fingers for the other thumb keys as necessary (one finger per key). The other hand presses the final key of the chord. This way complicated combinations like Ctr-Alt-Shift-F3 (or because of layering it is actually Ctrl-Alt-Shift-LayerShift-3) are easily doable. This is possible thanks to the fact that all modifiers are on thumb clusters. I never regretted moving Shift to the thumb cluster
Edits in italic.