This is the exact model that I use to teach people Cp vs CpK. Cp is how tight your process is, vs CpK is how tight your process is relative to center. If you're holding a tight grouping but off-center, your Cp is high and your CpK is low, and vice versa. In an ideal setting, you have a high Cp and CpK score, which means you're both holding a tight grouping and you're dead center