A friend linked me to IBM Watson Personality Insights service. Much, like Corwin and his use of the Trumps, I was certainly not using it in full accord with its author's intention, as it was intended more as a tool to analyze the personality of an author by what he has written, per the guidelines "Ideally, the text should contain words we use in every day life relating to personal experiences, thoughts and responses."
However, I figured the first-person nature of Corwin's narrative would be close enough to apply. So I pasted in the first three chapters of Nine Princes in Amber, and this is what it told me about Corwin's personality. I thought it was pretty good, right up until the end.
You are sentimental, somewhat compulsive and can be perceived as shortsighted.
You are laid-back: you appreciate a relaxed pace in life. You are down-to-earth: you prefer facts over fantasy. And you are organized: you feel a strong need for structure in your life.
Your choices are driven by a desire for well-being.
You are relatively unconcerned with tradition: you care more about making your own path than following what others have done. You consider helping others to guide a large part of what you do: you think it is important to take care of the people around you.