both but i prefer d4
Great games emerge from e4. d4 is very bookish and boring, imo.
chessboard doesn't care about "bookish or boring", it only cares about logic.
f3 i think is classified as A00 for unusual opening. It does not mean that a good player cannot play it and win, a strong player probably can
I always used to play 1 e4. But, for variety, for the past year or so I've sometimes been playing 1 d4 with decent results, so I expect I'll keep playing both.