I know, but I was wondering if that word is commonly used as a noun in English. I've only seen it used as an adj. Sorry should have been clear.
It is an adjective here. Both "unpredictable" and "strategic" are adjectives.
It is still an adjective in this context. English becomes more and more copula-dropping – i.e. leaving out the verb "to be" when it can be implied by context. If you add it back you can see how it's an adjective:
The opposite of (being) unpredictable is (to be) strategic.
Oh yea makes sense now. Thank you for your comment.