That's what I was saying, have both systems available and let players use either at will. I'd have to come up with letter and number sprites to put on the map though. Which actually seems impossible since each sprite is 16x16 pixels, and each map is well over 9x26 tiles in size. I would need to squeeze double digits or double letters (such as coordinate AA12) into both axis, and I wouldn't be surprised if I needed to use 3digit numbers and letters as well. It simply won't fit in a 16x16 sprite size.

And there's no way I'm going through literally every single sprite I have and increasing the resolution at all. First of all it would look terrible, and secondly it would be way to much work after I've made the game for 16x16 (which is what the GBA games are played in anyway).

That's pretty much why I've elected to use displacement in X/Y instead of chess-like coordinates. It's not possible, and forcing it would ruin the game.

---

If you ever took highschool math then you should be fine. +X is to the right and -X is leftward. Think of it like reading. We read to in a rightward direction, moving this way is going "forward" which is a positive change.