I don't know what kind of incubator you are using, but I got a 3d printed divider off of etsy for my Nurture Right 360 and it has seriously cut down both my rates of splay-leg and kamikaze chicks knocking into all of the eggs.The one that was zipping hatched. It was a hard hatch I think. She got stuck in the rubber band and she couldn't get her feet out of the eggshell. But she is fine now, currently resting in between two eggs.