When I was playing/reading these (e.g. Livingstone's) as a child I found a pattern. Always choose the lower number if you are unsure. (Or higher if that worked,

When I was playing/reading these (e.g. Livingstone's) as a child I found a pattern. Always choose the lower number if you are unsure. (Or higher if that worked, and if it does work, stick with it). I'd like to compare those maps now.