The 16" to 18" of chain gave the coyotes enough chain that they couldn't reach the end of it over the top of the trap stakes and pump them out of the ground. The three links of 3/16 " chain let me put up to three trap stakes in the ground if need be. they would be put at an angle to each other so as to bind together and make removing them nearly imposable at the same time but easly removed one at a time when I wanted to. the round shape of the chain links allowed the chain not to bite into the stakes and help with the animal being able to jack the steaks out even if only one steak was used. When you buy an offset jawed trap the trap jaws are stamped out so then the inside edge of the offset is sharp so I would take a file and break the sharp edges so they wouldn't cut into the skin helping with the holding power of them in that way. A lot of people like to put another piece of metal on the frame of the trap that has a dee ring in the middle of it so they can then swivel their chain from the center of the frame. I experimented with that, I did that to a few traps then put the swivels and chain at the center of the frame, put the trap on a coyote's foot and pulled it with a jerk. then took the same traps and swiveled them at the end of the frame and repeated the process. I consistently took more to pull the trap off of the foot with the swivel at the end of the frame, the foot would slide to the opposite end of the frame and then the springs put more tension of them as well as the spring lever on the swivel end raising higher on the jaws. Thats just my observations.