#3 Unai Emery's sharp tactics
Unai Emery is one of the best learners there is. Being a Spanish manager, he does not believe in winning the game with physicality or luck. He rarely gets his decisions wrong, and the games are won in his mind even before the whistle.
Emery tends to study his opponents thoroughly before stepping on the pitch. He prefers a three-man defence for sides who tend to play on crosses and headers but chooses a 4-2-3-1 against sides who play possession-based. However, lately, he has stuck to the three-man defence as he plans to concede less. But keeping a clean sheet against Liverpool is more difficult than finding a needle in a haystack.
His tactics change from game to game are proof that the manager doesn't believe in a permanent starting eleven. His line-ups keep changing from game to game, and that is the speciality he has, which has certainly paid off for Arsenal.