As white my most common opening is e3, then knight to f3, then knight to c3, then d4, almost regardless of what my opponent does. It works 30-50 percent of the time.
Hmm. A piece down and your king stuck in the center after only 6 moves. That's not good.
A lot of people like to play a system where they play more or less the same moves without regard for what the opponent does. However, your system leaves your knight open for immediate attack. You lost it quickly.
If you had opened with d4 and then followed with Nf3, Nc3 and e3, there would be much less chance that you would end up down a piece and with your king stuck in the center after only 6 moves.
Of course, any system like that has its drawbacks. You might consider taking some of the free Chess Mentor courses on how to open a chess game.
As white my most common opening is e3, then knight to f3, then knight to c3, then d4, almost regardless of what my opponent does. It works 30-50 percent of the time.