This was a lot of fun to read! I had been wondering who the gent that came to play chess was and, well you should read to find out who B-)
One point of feedback that I would mention is the introduction to the piece. While I can see establishing the character of John, as well as elaborating the situation, I think that it may be a touch long overall. I wouldn't know what to cut since it all seems important, but perhaps it could be condensed slightly?
One thing I will say is that you paint a very vivid picture, and I feel like all the major characters from the setting were appropriately portrayed. I'd be interested to see a follow up to this :-)