I quit calling and shoot as soon as I saw the coyote. But wait......... that was usually 30 or 40 yards. In one case, it was less than 3 FEET. (of course, by the time I got a shot off, he was WAY OUT THERE, about 20 yards.....) /ubbthreads/images/graemlins/laugh.gif
OK, seriously. The answer depends entirely on what kind of country you hunt.
If you are watching one, and wanting him as close as possible, watch his body language.
Stopped, directly facing you, he will probably come closer.
Stopped, sideways, SHOOT!!!!!