Not so much A-B testing as L-R testing.
M’colleague, @RaeofSunshine24, played this video in a meeting on Friday:
Inspired by this, I took off my right shoe and re-tied the lace.
It seemed to work at first, but I wanted to be sure, so what would any self respecting geek do in this situation? Yes, testing!
To test any theory you need a control, hence split testing on websites, so I nominated my left foot as the control and re-tied the lace in the traditional manner.
Initial results after two days suggest that the left shoe is looser than the right, so it looks good for the new knot.
https://www.ted.com/talks/terry_moore_how_to_tie_your_shoes