Most Tottenham managers are given the same piece of advice when they first take control in north London. Whatever you do, make sure you beat Arsenal. If you can't win against Arsenal, make sure you beat Chelsea. And do not - under any circumstances - lose to West Ham.
Nuno Espirito Santo will have understood the importance of derbies when he was appointed, and - throwing in a 3-0 defeat by Crystal Palace - he has now committed the cardinal sin of losing four of them and conceding 10 goals in the process.