I am almost at 100% when they come in hot and slam on the brakes then stand still for a few seconds. Anything within 200 yards, broadside or head-on, is dead meat.
I use to open up on fast walking or running coyote, the kind that come running to the call but then swing off wide in one direction or another still looking back at the area of the caller. Unless they are within fifty yards or so when they swing away I've finally developed the required discipline to just let em go.
My last kill was a runner who came in kind of fast but never slowed down no matter how much whistling or barking I did. He came in from left to right and passed by me at about 45 yards. I grazed his head right before he entered the wood line on shot #3 iirc.