Very few coyotes won't run when they small a human, so the likely hood of a confrontation is very small.
That said, I've had a few come harrass my dog on occasion. On or two would walk up near the house and try to lure my dog away from the house. Then, once he was in an opening the pack would circle him. If you find yourself in this situation and you have a second to observe the situation you might find the pack's alpha standing back a bit from the situation, he'd be the one to take. If you can't place him, take the largest coyote. If you don't have time to size them up, do what I did and kill as many as possible.
If you're lucky you'll get two....
later,
scruffy