Pinto just means the horses is a colour + white.
The name of the pattern indicates what sort of Pinto the horse is.
So if I said my horse was a Chestnut |Pinto you would know it was Chestnut and White but that is all.
If I said my horse was a Chestnut Tobiano Pinto you would know it was Chestnut and White with no white on the face, probably four white socks, ...do you see where I am going with this??
Your horse is a Chestnut Splash Pinto BUT he may also have Tobiano and he may also have Frame and there could also be Sabino in there!!
You can test for Frame, which I definitely would do.
He is, visually at least, definitely Splash.
What patterns are his parents??