Award yourself a point for each cliché spotted.
1. The protagonist is separated/divorced/widowed/has just emerged from a toxic relationship.
2. Their new love interest turns out to be the villain or winds up dead or possibly both.
3. They had a traumatic childhood (abusive father, alcoholic mother, or whatever).
4. They drink too much (regularly or a single binge: either is fine).
5. They have a difficult relationship with a child or sibling.
6. They screwed up their last case and must redeem themselves.
7. One of their subordinates is secretly undermining them.
8. Their superior is threatening to take them off the case.
9. Someone who is about to give them vital information is found dead.
10. They confront the villain without waiting for back-up (or dialling 999).
If you read a novel (or watch a TV programme) which contains all ten – and it does happen – award yourself double points. And for writers, while it’s possible to write an excellent novel containing some or even most of these elements, it might be best not to throw the whole lot in.