In this linked thread, @Exapno_Mapcase asserts that in a cozy…
the detective is someone very much a part of the community, knows the people and deals with them regularly, and so can make assumptions about their behavior.
I guess this is a valid distinction. I my mind I had lumped Poirot in among the cozies because so many of Christie’s other stories are, and he meets most of the other criteria we’ve listed.
Someone will correct me if I’m wrong, but ISTM that with these criteria, the BBC Father Brown with Mark Williams is a cosy, but Chesterton’s originals, for the most part, are not.
I have read a good percentage of the short stories, and none that I can recall featured any of the stock characters of the show, and many of the tales were set in various European cities. Does the series draw anything from the originals other than the basic character of Father Brown?