> Plus, the numbers are also split by hand!
> From middle-going-out:
> Left hand: 91357 Right hand: 02468
What is the advantage of this order vs. numerical order? If I'm reading your post correctly the numbers are arranged 7531902468 on the keyboard, with maybe a space in the middle? Is there some mathematical property where odd and even numbers are more likely to alternate than for odds or evens to be found side by side? Maybe 0 is more likely to appear so they want it on an index finger? It just seems unlikely that the next most common digit is 9, unless this was developed by people who set prices on items.
Very simply: if it's an even number, it's your left hand. If it's an odd number, it's your right hand. If you want to type a number like 2,467,333 you can do it without looking for the numbers. On qwerty I tend to "lose my footing" when it comes to typing numbers out. But if it's a 2 on programmer-dvorak, it's right hand, index finger. 2468 is each of your four digits, in order. and 1357 is the other hand's digits. However, I hold left-shift to access the numbers which means my pinky is unavailable for the left numerical ascension, so I tend to do 1 and 3 with my index, and 5 with middle, and 7 with ring. Nine [9] and Zero [0] are "stretch" numbers in the middle: 9 and 0 are reached via one's index fingers going diagonally toward the middle of the tippy-top row.
tl;dr: right hand even,, left hand odd,,, increasing from index to pinky. "Look ma, no eyes!"