Only if you do not sharpen the knife on the machine with a magnetic holder, as I sometimes use - a compass in the handle will go crazy and look down or up rest of his life..
or have a permanent error, which must be taken into account.

https://www.youtube.com/watch?v=aip4ga_pweU
I was there in 2013, but in the shot did not enter.

but it's a very rare case


The wrist strap is not always used, but I cling to a bright ribbon, so as not to lose the knife in a forest or field, where it merges with the earth and grass.

I thought the night, I vote for the wrist thong.