no it's a really good question! I think this just has to do with the line detection algorithm and it tending to find more curves than sharp angle lines -- this is what the matches look like when you draw a Z:
they are not as good as when you draw a curve and I think it's just trimming based on general poor matches. I've found if I round the Z or make the angle less extreme I can get better results.
http://imgur.com/a/YErmM
they are not as good as when you draw a curve and I think it's just trimming based on general poor matches. I've found if I round the Z or make the angle less extreme I can get better results.