A YouTube Tail Chase or YouTube Tail Chase Loop, refers to the endless re-buffering of a video during streaming. With the loading of Youtube videos comes a circle, with smaller circles going around it. This circle icon appears in the middle of the video during the streaming process. These circles look like a dog chasing it's own tail around in an endless circle. YouTube Tail Chase Loops commonly occur when trying to watch multiple videos at once. If a 1 minute video Re-Buffers 5 or more times, then that can be considered a YouTube Tail Chase. And if a 5 or 10 minute video that never finishes playing, because it doesn't come out of the rebuffering process, is then considered a YouTube Tail Chase Loop.
I got stuck in a YouTube Tail Chase when I was trying to watch a clip of some dumb kid who lit himself on fire. It took me 15 minutes to watch a 2 minute clip!!!