conventions used by agatha chrisite? (1 Viewer)

[bEAbEA]

can anyone think of any of the conventions of crime fiction that agatha chrisite uses in her writing?
I've thought of the closed house and whodunit sub genres that she uses, and also the use of detectives who have morality and principles but anymore would be appreciated..

 

[waterbottle]

the denouement: her detectives always have a stroke of genius and are able to untangle the mystery even though they've been given a bare minimum of clues.