noun
armchair detective
Refers to a fictional detective who solves crimes from home without visiting the crime scene, or a reader who tries to solve a mystery before the fictional detective does. Often used in discussions of detective fiction.
See also: アームチェアディテクティブ
安楽椅子探偵ものの小説が好きです。
I like novels featuring an armchair detective.
読者も安楽椅子探偵になって犯人を推理する。
The reader also becomes an armchair detective and deduces the culprit.