I had 1 so far that was fully developed and pipped and cut an entire ring out and got stuck and died. Other than that it's looking like I got 19 out of 20. Really cute healthy little things. This photo was right after I tried vent sexing all of them (to further familiarize myself with the process). And much like anything you want to be able to do well and proficiently, it takes practice and experience. I'll feel much more confident the next couple of batches I do.