as many have said, thank you for this! I'm thinking of trying to write a Spider player, but it's been 20 years since I've ever coded anything this complicated (and don't really know java)! Should be a fun project once I get into it.

One suggestion... --show-prompts prompts you at the initial scan, any duplicates, and for permission to solve. I would like to see --show-error switch that only pops up when duplicates are detected so they can be corrected. This would make living with the Queen of Clubs issue easier. :)