In fact, this tendency of original surveyors to repeat the same
errors, can be a very useful tool when your intent is to retrace
the steps of that original surveyor as a proper resurvey should
do. This technique is called index correction for average error.
Certain characteristics or patterns may be discovered by retracing
a given surveyor's lines from many miles.
These patterns reflect whether he chained uniformly short or long,
or was uniformly off to the right, or left of his record bearings.