The last move numbering scheme is mathematically correct but not ergonomical.
It is not natural to use negative numbers to number the last N moves; most go diagrams show move numbers incrementing from 1, I have never seen negative numbers.
Using negative numbering makes it more difficult to mentally replay the sequence (the user has to search for the lowest number, then increment a negative number, all this asks for additional brain bytes.)
Also, the '-' sign uses precious screen estate but has otherwise no value, other than force the user to order the moves mentally.
The advantage of negative numbering might be that it allow to find the latest move (which is always -1).
Please consider labeling the last N moves using <i>natural numbers</i> from 1 to N, when N is the most recent move, or add an option to choose between the two modes.
Some notes: - I'm not sure what the difference is between edit numbering and move numbering. - What is D-Pad?
Author response:
edit numbering and move numbering allow you to use different numbering parameters for the game editor vs the client. The preferences for these allow values from -9 to 99. negative numbers will count backwards from the current move (the mathematically correct option) positive number will number like most diagrams.
D-Pad is a physical directional pad on some ancient phones.