Mound vs. Flat Ground

Will pitching on flat ground vs. a mound have any impact on velocity and movement? If so, then how much of a difference?
The reason I ask this is because I pitch in my backyard on flat ground against a wall. My friend and I recently went to our friends ranch and we made up a crude mound which was pretty much just a slanted hill and I did terrible! My control was off and my velocity was definately not as fast.
Is this just because I’m not used to the slant?

Typically, your velocity should go up on a mound. The lack of control is probably just because you are not used to it. It takes time and practice to get used to a mound!

Flat ground your breaking balls (if you throw one) aren’t gonna have a lot of “snap” to them. Flat ground also puts less stress on your arm (which is a good thing). Just focus on staying back more when your on a mound and getting good extension, those two things should help.