Oh yeah I know, i also figure in the wind, since I usually firing so that "gush" of wind will cover up my silenced sniper rifle being shot, as well as carry the BB (may seem useless to you, but has helped many times for me).
@CDN_Stalker or you just your carpte of BB bastards to guesstimate the shot

But in all seriousness, thats how i found the length of my stride. I wear size 13 boots, which is about 12. 625 inches, which multiplying by 3 (length of stride) gives you about a meter. And I did use a football field at first, since I played the sport in high school, as the QB
@FOX_111 I dont use fingers, I instead use the "mile markers" i was talking about since they too will be at 15 foot distances, so if someone is about 3-4 inches tall next to the 7th "mile marker" which is +/- 105 feet. I do use the mil dots on the scope as well, thats usually how I place the "markers"
But then again, I apply real steel sniping methods to airsoft, yours is cemented in the sport, so its why its more reliable to you