I looked through the various posts but saw nothing on a related matter, i.e., sliders. It is my amateur knowledge that a slider is a fastball that breaks (usually at the knees) just before reaching the plate. No? Otherwise, what the hell is it?
It’s like half curve/half fastball. Its break is less than a curve, the deepest part is right up by the plate idealy, like you said. I think most people consider it a type of breaking ball, but it usually is a heck of a lot faster than the standard curve.
Freegards
In simple terms, a curve is basically vertical (12 to 6 break). a slider is more horizontal and from the same pitcher be about 5 mph faster than a curve. A "slurve" is more or less diagonal, not a true curve and not a true slider but none the less still pretty tough to hit.