good at, adept at, and excel at

Question

• What are the difference between good at, adept at, and excel at?
• What are the occasions where one is more fitting than the other?

While I was writing this question, I stumped over another conundrum: should've I used fitting or befitting? & How can they function differently?

I searched for the cut-and-dried answer in several sites, but no such luck.

Answer 1

Thanks to @TeacherKSHuang here is:

• Good at - average, not great but not bad.
• Excel at/in - very good at.
• Adept at - usually involves a physical rather than a mental skill such as throwing a ball, hammering nails, or driving a car. Applies to "fine motor control" such as sewing rather than "gross motor control" such as running.

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• Excel at - more with sports and gross motor control, such as basketball or hockey.
• Excel in - more with mental things, like playing chess.

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Excel at and Excel in are fairly interchangeable.

You could use "Adept in" before, however, it's archaic usage and "adept" can also be a noun as in:

• "He is an adept in football."

I would add to @Sedgehead's answer that:

• "Adept at" - mostly means very skilled or proficient at something.

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Summary:

You can be good at/in {doing} something (but not proficient), you can be excel at or excel in (Excellent) {doing} something, you can be adept at/in, proficient at/in/with, skilled at/in/with, expert at/on/in or skillful at/in/with.

Here are examples of using these adjectives with prepositions adept, skilled, proficient, skillful, excellent and good.