In the pet trade, there are three species of short tail pythons; red bloods, Borneos, and Sumatrans. They are all very different in color, markings, scale count, and the shape of the head. It is also rumored that Borneos and Sumatrans are, on average, a bit smaller and more docile than red bloods, but if so not by much.
I find Kara's page to be most helpful when it comes to identifying short tail species.
http://www.bloodpythons.com/cms/
For most people, it's the names that are most confusing. Borneos and Sumatrans are often called bloods.
Python brongersmai, red bloods from Malaysia and Sumatra, have much red pigmentation and an overall rugged appearance. These are your typical "bloods".
Python breitensteini, Borneo short tailed pythons, also known as Borneo blood pythons, breits, BSTPs, or just Borneo pythons. They are native to Borneo (can you believe it?
) and have the lightest color of short tails. Out of the three species, most of the lower-quality ones are Borneos, but if you get a really really high-quality Borneo, they are the most beautiful of the short tails, imo. Breits are my faves. No other snake has the same peachy and chocolate-y colors.
Python curtus, Sumatran short tailed pythons, are mostly black and silver. They are often nicknamed black bloods, Sumatran bloods (which is especially confusing because there are also Sumatran red bloods,
Python brongersmai from Sumatra), Sumatran pythons, etc. All in all, don't bother trying to interpret the name. If you want to know what species a short tail is, refer to its Latin name.
Those are the three species kept in captivity. Among those species there are morphs such as cherry and albino bloods, marble and ultra Borneos (usually known as ultra breits), chrome head Sumatrans, etc. Personally, I don't think it gets any better than a nice clean normal, but if people want to play around with their genetics, I don't have a problem with that.