Agreed, I know Blink can actually be frustrating to deal with, but it's also quite difficult to master, this said, if you use Blink outside the Blink-Shotgun combo and know how to use it, you'll be VERY difficult to kill. On the other hand, as the OP said, 99% of the time the Blinker will head forward or up, so it's 99% predictable, when you see the animation of a Blink just aim your Shotgun up and shoot, in the worst case will be a trade-kill.