Whether your synth is velocity-sensitive or not, there are characteristics of the sound that can be controlled by your touch. I’m talking about the way the synth triggers its envelope generators based on notes that are played detached, or connected

Not all fingers are created equal, it seems. Most keyboardists find that the 4th and 5th fingers (the ring finger and the pinky) are somewhat weaker, and a little harder to control when trying to play passages smoothly/in perfect rhythm.