By "apples to apples" I assume you think that the systematic error is as consistent as your technique. However, what I've found is that the error is related to the type of terrain. An extreme (but not necessarily uncommon) example is traversing along the side of a cliff with a steep slope above. It is easy in that case to accumulate more elevation error than in cases of more smoothly varying terrain. In a similar vein, measuring the length of a trail that switchbacks up a steep slope is much less accurate than a straight trail since maps often do not always faithfully represent the trail.Hobbes wrote:Whether the mileage distances and/or elevation gains/losses are accurate isn't necessarily that important (as it pertains to me) as long as I have a consistent history. That assumes, of course, that I use the same basic techniques for measuring & evaluating different hikes. Since I think I do, and because I keep track of my actual time for each major section noted, then at least I'm comparing apples to apples (for myself).
Maybe that level of sporadically greater inaccuracy is of no consequence to you personally; maybe you're not even aware of it.
In any event, over time everything averages out, us included.