In my experience many people define pace the same way today. We were taught in Boy Scouts how to pace off a distance measuring 5 feet per pace, or every other footfall.
I have seen this argument before, but I'm not sure that I buy it. Even if you count every footfall, you are not magically going to somehow use, say, only your left foot. At the end of a km, you will have 600 double paces or 1199, 1200 or 1201 single paces. Well within the margin of error.
My hypothesis is this: Actually try to count every foot when you’re out. If you count only every second footfall, you can mentally go "a-one-a-two-a-three" and so on, but counting every foot, there are just too many of them. At least I get brain overload from it.
Nope. Boy scouts, not cub scouts, so a lot of us were closer to adult stride than kid. If you measure a typical adult pace (same foot to same foot) it's probably just under 5 feet unless they're deliberately pacing to measure something. You get a feel for what it takes for your own pace to hit 5 feet so you can repeat it.
I used to teach orienteering and scout skills when I was a teenager. One of the first things we did was measure how long each kid's natural pace was so they could know how to pace out a distance. If the course said 600ft and the kid knows their pace was 3 feet then they would take 200 paces or 400 steps. Typically, unless you were a runt like me it almost always came out to 5 feet. Just kind of the way people work. 2.5 feet a step. Roughly 5 feet or 1.5 meters per pace.
It always got complicated with obstacles though. Especially since most of them didn't know how to do trigonometry yet. We usually just had them estimate which they got pretty good at after a few hours of counting paces.
Averages out better.