I answered this question at chess.com: "Which openings would you suggest me to study for White and for Black against 1.d4 and 1.e4?"

"Which openings would you suggest me to study for White and for Black against 1.d4 and 1.e4?"

I'm lazy so I figured out a way to study openings as little as possible. As White I decided against moving e4 or d4 on the 1st move because that would require an understanding of countless replies from Black. So as White I always play the King's Indian Attack. As Black if White's 1st move is e4 my reply is always the Sicilian Defense and I often wind up playing the Najdorf Variation. As Black if White's 1st move is anything but e4 I play the King's Indian Defense. My plan has worked. I can survive the opening knowing just 2 openings, the Sicilian as Black, and the King's Indian as both Black and White.

http://www.chess.com/forum/view/chess-openings/positional-openings4

By the way, chess.com sucks.

https://lichess.org/ is much better and it's free.