I am not sure if Strategy ( or Policy ) pattern is any different than polymorphism + encapsulation of OOPs.
I am raising this because other patterns like factory , singleton ( simple though very complexed in multi-threaded case ), have something other than language feature. And I believe Pattern should be more than OOPs concept.
Strategy pattern, in my view, is just a use of Polymorphism and obviously better class design would encapsulate it.
Let me know your thoughts on this please.