With ball pythons, you can get piebald babies from the following crosses:
1. piebald x piebald --> all piebald
2. piebald x heterozygous piebald --> 1/2 piebald, 1/2 normal-looking (heterozygous piebald)
3. heterozygous piebald x heterozygous piebald --> 1/4 piebald, 2/4 normal-looking (heterozygous piebald), 1/4 normal

You will not get any piebald babies from the following crosses:
1. piebald x normal --> all normal-looking (heterozygous piebald)
2. heterozygous piebald x normal --> 1/2 normal, 1/2 normal-looking (heterozygous piebald)
3. normal x normal --> all normal

Paul Hollander