In regards to the exact placement, I find it hard to combine the outright principles (optimizations) behind Dvorak and Thumb-Key, especially the two-thumb layout. They all have their issues they are trying to resolve.

I prefer the alternating keys to rolling-keys. Especially when typing on a screen. That makes Dvorak a better fit than other layouts.

Dvorak layout, when preparing for Thumb-Key, ends up being like this

I’d be targeting Dvorak layout but the principles are the same for any layout to be applied to this frame.

Isn’t this essentially a duplicate of https://github.com/dessalines/thumb-key/issues/592

Perhaps we could use the idea behind the two-hand layouts and have two identical 3x3 grids. However, this layout is having the last column squashed on my phone and is not that practical. I think we could remove the middle row to gain space. There are only 2 keys in the middle row that are actually useful. The third - backspace - is completely redundant as it appears three times on the screen. Reducing Space to 2 slots would also provide one extra slot.

One possible way to place the space key:

This would be a good starting point if creating a new layout instead of adapting an existing one (like Dvorak).

Pros:

• That would eliminate the need for the bottom row, which traditionally hosts the key.
• special characters and options can be placed as swipe keys

Cons:

• space is also needed for other special characters, which need to move to the main 3x3 grids
• special characters can’t be placed in the middle duo to symmetric even layout
• the characters from the bottom row need to be jammed into the top two or elsewhere

How do I pick the most-common letters from the middle row when those are the most common letters overall?

@dessallines, what were your guiding principles in positioning the keys? I guess we could use the same, just adapted for the two hands.