At the Visalia range, which is basically a bathtub with near vertical sides that are right next to shooting lanes, a shooter's flags often disagree with each other and switch rapidly. For me, having vanes with different colors on each side makes it easier to remember the condition that a group starting shot was fired in. I understand that there are ranges where the prevailing conditions generally have all the flags blowing in the same direction. Wouldn't that be nice!
One thing that recommend to shooters who are in the process of choosing which flags to buy, is that they spend some time studying them at a match, to see which ones are the easiest for them to keep track of. Looking at what is out there, this may vary from person to person.
Boyd I can think of many open ranges where that doesn't happen, I was starting to think it was a myth started by someone to confuse us.
I've quite often seen flags about 4' apart with their props spinning and pointing at each other and the tails straight up in the air......all that does is tell me not to shoot.
My flags are quite twitchy in some conditions but occasionally I've seen a flag switch direction 180 deg just after I've pulled the trigger, if I'm real lucky the bullet went in the group but mostly its gone where that flag twitched too and usually by quite a way as I was holding that way too.