Both. You are limited to a maximum of 16 files and 16 ranks. But there is also a limit of 192 squares, so you can't really get 16x16. The largest size is essentially 16x12 or 12x16. Someday this might be increased, but not any time soon. Going to 16x16 would not be too large a code change, but it would have a performance cost for every game, even small ones.
I was thinking of trying some very wide boards, like 8x20 or 8x24, which would fit the 192 squares limit. Is the reason for the 16 file and rank limit that larger dimensions might be more difficult to display clearly?
I was thinking of trying some very wide boards, like 8x20 or 8x24, which would fit the 192 squares limit. Is the reason for the 16 file and rank limit that larger dimensions might be more difficult to display clearly?