If you line up 20 or more zombies and shoot them down there is a bit of a frame rate delay.
But with 20 or more hit markers all entering your screen at once...
Butterflying would be so ridiculous :P (butterflying is what I call circle kiting a train and hip firing at them at the same time. Idk if there's a better word for it)
Ding ding ding. More common though is the term, "raeptraining"
I've been using 'kiting' since WaW, and for me it was an invention of my own. The term 'butterflying' that I'm using is referring to a different type of kiting. There are 4 distinguishable types that I've named, circle kiting (the most common), path kiting, reverse kiting (the most advanced technique) and butterfly kiting. Each of these will result in a horde or 'train' as many of you prefer to call it.