"... it's a question of weaving the net of coincidence as fine as possible."

Martin Beck's philosophy of police work in a nutshell:

Police work is built on realism, routine, stubbornness and system. It's true that a lot of difficult cases are cleared up by coincidence, but it's equally true that coincidence is an elastic concept that mustn't be confused with luck or accident. In a criminal investigation, it's a question of weaving the net of coincidence as fine as possible. And experience and industry play a larger role there than brilliant inspiration. A good memory and ordinary common sense are more valuable qualities than intellectual brilliance.

From Maj Sjöwall and Per Wahlöö, The Abominable Man (Translated from the Swedish by Thomas Teal) (1972).