In The Equalizer, Denzel Washington is basically inside of his head a lot. He does a lot of thinking and watch checking while deciding how he’s going to beat opponents. It is an element he, not the director, brought to the film.
The Equalizer is constantly calculating how he is going to make his next move, and the amount of time it will take. This psychological tick is characteristic of obsessive–compulsive disorder, abbreviated as OCD.
Though OCD is seen as a disability, in Denzel’s case it seems to give his martial arts supreme effectiveness. It allows him to figure out a few moments ahead how he’s going to defeat adversaries. It also allows him to do it as quickly as possible.
It’s just like playing chess or sight-reading music, where the ability to think ahead can determine success or failure.